The ALL Pro and Pro Lite controllers use the same transistor and controlling circuitry.  They all have adjustable Sensitivity and Brakes.  Coast, Choke and multi range Sensitivity and Brakes are the only options.
Are you racing HO or 1/32? The main difference is in the selection of the Brakes and Sensitivity Range.
1.   Decide whether you need the full HO range or just the Vintage range. If you race SS magnet cars occasionally and nothing stronger then the Vintage is your choice.   Otherwise choose the HO version.   If you run GJets/ViperJets or similar then you need the HO version. The HO version will cover the entire range of the Vintage version.   The Vintage version will have greater Tjet Sensitivity control with their lower range.
2.   Choose the Pro Lite if you require Adjustable Brakes and do not need Coast or Choke.
3.   Choose the ALL Pro if you require Adjustable Choke or Adjustable Coast.
Note: The Vintage and HO ranges will both run a Tjet the same way. The only difference is the amount of Sensitivity Knob rotation. For example, the amount of rotation covering the T-Jet range will be greater on the Vintage controller than it will be on the HO controller.  This greater amount of rotation permits a finer adjustment of the Sensitivity.  The ALL Pro, with its multi range selection switch will have even greater Sensitivity control than the Pro Lite.
1.   Both 1/32 controllers have adjustable Sensitivity, Choke and Brakes.
2.   Choose the 32 ALL Pro if you want multi-range Sensitivity selection and multi-range Brake selection.
3.   Choose the 32 Pro Lite if you only need one Sensitivity and Brake range for all cars.
This is the biggest issue with any controller. Making it feel comfortable to your driving style. So why does one controller feel right and another not. Once the sensitivity, Brakes/Coast and Choke (if desired) is set to your normal setting the feel of the controller comes down to three main reasons.
1) Start and Stop positions - Is the trigger throw the same as your old controller?  There isn't much that be can done with the throw once the controller is designed.  Most controllers do have throws very close to each other as a standard.
2) Trigger - The Parma Turbo trigger has become the standard in most after market controllers.  To some this squared edge trigger can rub the finger wrong and alter the feel, especially if your previous controller used a Parma Econo, Red Fox or PM trigger.
3) Trigger Spring - Absolutely the single most important aspect of your controller's feel.  It is the most overlooked component of the controller.  Just like a weak or strong gas pdeal in a car makes the whole car drive different, a trigger spring changes how the controller responds.  If your previous controller had a stiff spring and this controller is weaker you will notice that the car is jumpy and reacting too fast for your driving style.  All the adjusting of the Sensitivity will not improve this feel.  Likewise if you are used to a light spring and the Pro Series spring is too strong the car will feel sluggish.  You will feel the need to have to pull harder to try to get the car to go.  Again, adjusting the Sensitivity will not change this feel.  We use the standard Parma Econo spring in the Pro Series.  This is a good all around spring.  We can make the spring tension lighter if desired and soon will have a couple of spring options available.
Choke is an adjustable dead spot between the last wiper band and the Full Power band.  By introducing a dead spot or "Jump" in power prior to Full Power the usable range of the controller can be increased.  Most cars navigate the curves and esses in the first half of the trigger movement.  With Choke, the upper limit of the movement is lowered allowing the entire movement to be utilized.  Choke also has the benefit of being useful for cars with tons of downforce when lifting of the trigger causes the car to slow down too much.  Instead of increasing the sensitivity up so high that the lower end is useless for the tricky section the "Jump" now allows the trigger to only be blipped back one band to settle the car prior to a turn.  This minimal trigger movement can greatly increase your response time and yield faster lap times.
Coast is a small amount of voltage applied to the car when the trigger is against the Brake Stop.  It can be used to reduce the amount of natural braking the car has going into the corners or to combat the strong downforce of magnet cars.  It is usually not used on non-magnatraction cars, like Tjets, that need every bit of Brakes they can get.  When set, Coast will usually not cause a car to move on its own from a dead stop.  Even though it doesn't make the car move it can keep it rolling once it starts or just give a little roll when the trigger is released.
When Coast is used, Heat is built up in the controller.  Under normal driving conditions the trigger is only briefly fully released (Coast Position) so the heat buildup is low.  If the Coast is left on with a car on the track this Heat will continue to build in the controller.  This occurs whether the car is moving or not. This heat can also be built up if the Coast is used to let a "Computer Racer" car do laps or when using Coast to break-in a car.  To protect the controller from the heat caused by this abuse a PTC resettable fuse is used.  To prevent this fuse from tripping under normal racing conditions it may take quite a bit of heat to cause it to trip.  The HO and V ALL Pros utilize a unique Coast circuit which keeps all the heat inside the controller and not in the potentiometer.  This fact should not lead you to believe it is bullet-proof.  The PTC fuse will still need the controller to get hot to trip.  Again this is to prevent it from tripping during normal driving conditions which has to be the main concern of design.
If the PTC fuse trips it needs to be reset to permit the Coast function to operate again.  This involves allowing the PTC fuse to cool.  The time to cool is dependent on how hot it was before it tripped.  Usually this takes only a few seconds as long as the condition that caused it to trip is removed.
Fusing is accomplished by MINI automotive fuses in the external handle wiring.  External fusing provides easy and quick fuse verification.  Just hold it to the light and see if the wire is broken.  These mini fuses are not sealed so when they blow a bit of smoke may be present along with a burnt smell.  This is normal when they blow.  It is quick and easy to remove and replace.  Can be done in less than 5 seconds and even during a race.  OS3 uses standard fuses vice PTC (Positive Temperature Coefficient) resettable fuses.  We have reviewed all the documentation and feel that fuses provide the best protection.  The OS3 controller is internally protected from short circuits but when the trigger is fully pulled, all protection is bypassed to provide full power to the car.  The external fuse is used to protect the track (where the short is most likely located) and the Power Supply (PS).  Fuses act very fast and trip in milliseconds when the current reaches 1.5 times the rated current.  The 5A fuses we use are designed to trip at 7.5A.  As long as the PS is capable of delivering 7.5A the fuse will blow during a short circuit.  When a 5A PTC fuse is used it is designed to trip at 10A.  The industry standard mandates that a PTC trips at its rated trip current in 120 seconds.  Personal testing reveals that this is right where they trip.  So it takes 120 seconds during a short circuit with a 10A PS to trip.  PTC documentation says that if you had a 25A PS the PTC will trip in 14.5 seconds.  In other words you have NO protection at all for your PS.  Using a smaller PTC will cause them to warm up under normal operation and increase their resistance.  This robs your car of power.  So when a racer says, "My controller has PTCs and doesn't need to be reset" what they really mean is "My controller has NO protection and I hope your PS and track survives."  We use 5A fuses so the commonly used MG PS10AD 10A PS can provide enough current to trip.  We offer a 7.5A fuse for those who want to ensure they don't blow a fuse during a race with this power supply.  It is highly recommended that the track have its own protection when using 7.5A fuses.
(Note the PTC fuses are perfect for protecting the Coast circuitry since the resistance is never zero and it doesn't need immediate response)
Controller - is internally protected against short circuits.
Brake Potentiometer - is not fused.  Fuses of any kind would be useless in the Brake circuit and would provide added resistance.  Since Brake potentiometer blow due to excess heat caused by incorrect hookup it takes little current to cause failure.  Using a fuse to protect against this low current would cause the fuse to trip under heavy braking.   Therefore NO brake protection is used.  If you hook up the Black and White clips backwards with the Red wire correctly connected (Brakes switch to B for the HO/V ALL Pro) you will send the full track voltage to the Brake potentiometer and have a good chance of blowing it.  It is ALWAYS recommended to have the Brake wire/Brake switch off when connecting and testing your controller.  Test the controller with only Black and White and see if the trigger controls the car speed.  If not, quickly disconnect and correct.
Transistor - is protected by design.  When the Black and White wires are reversed the transistor will power the car without trigger control.  It will send enough power to the track to launch your car off the track.  While this is good for the controller it may not be for your car.  It is ALWAYS recommended to remove cars from your lane prior to hooking up your controller.  Then start with the Black and White wires first as per the Brake potentiometer section above.
Coast - See Coast section above.
A fuse blows when current in excess of its rated limit flows for a certain amount of time.  To have a fuse blow in an effective time the current needs to be 50% higher than the rated current.  A 5A fuse will blow at 7.5A, etc.  If you are running anything less than a 7.5A power supply, your fuse is rendered useless and will not protect your controller.  It is highly recommended to run the Pro Series controller with at least a 10A Power Supply.  Lower amperage Power Supplies may still work depending on the number of cars on the track and the normal current draw of those cars.  If the cars on track draw 2A total then 9.5A would be required of the Power Supply to blow the fuse.
So, what makes the fuse receive this excess of current?  Racers send us numerous emails asking why their controller is blowing fuses.  To date, we have never seen one of our controllers that actually caused a fuse to blow.
In a controller, the White wire is connected to positive of the Power Supply.  The controller determines how much resistance is between the White and Black wire and current flows to the track through the Black wire to one shoe of the car.  The other shoe of the car is connected to the negative side of the Power Supply. When the trigger is fully pulled the controller reduces the resistance between the White and Black wire to 0 to allow maximum power to the car.  Here, the only resistance in the path is that provided by the car.  If the current flowing through the White wire exceeds the Fuse's rating it has to be due to the car's resistance being too low.  This can be caused by shoes shorting out during a spin or the stall of a low ohm motor (SS arms at 6 ohm will draw 3 amps on stall, Mods can draw 6 or more).  In two wire operation there is NO WAY the controller can overload the fuse by itself.  Properly connected in three wire operation the controller also can't blow the fuse. If your fuse is blowing ALWAYS check the car.
When connecting your controller, hook up the White and Black wire first and test a car to the track.  If the car revs at full speed then the White and Black are backwards on the track and you need to reverse your White and Black wires.  This is not uncommon on two-wire only track where mainly resistor controllers are used.  Test the controller to see if you have control of the car's speed.  If not then there is still a track wiring issue.  If you are using Brakes and, assuming the White and Black wires are correct, hook up the Red wire.  It is always a good idea to keep the Brake potentiometer at Min or have the Brake/Off/Coast switch in the Off position when hooking up your controller to protect the Brake potentiometer.  If you hook up the Black and Red wires across the positive and negative posts, the Brake potentiometer may be damaged.
DO NOT OIL the Wiper Board
The wiper board requires occasional cleaning to keep the wiping action smooth and prevent the bands from shorting.  To clean the board just use a Q-tip or paper towel and alcohol to wipe the dust from the grooves between the bands.  As the wiper button wears down the dust falls into the grooves between the bands.  This is most noticeable when it falls into the gap between the resting and first band.  Dust in this area can arc weld itself between the bands and be very difficult to remove.  The symptom of this is that Coast will ALWAYS be on.  If running Brakes it will keep power constantly applied to the Brake/Coast potentiometer and can damage it.
Pro Series controllers have the handle cut open by the wiper board for super easy quick cleaning without having to disassemble the controller.  When the wiping action starts grinding it usually only requires a wipe across the board with your finger.  If it is still grinding then you can slide a piece of paper under the wiper and clean under the button.  Wiping with your finger will not only remove the dirt but it will also apply a little finger oil to the board.  This is the only substance recommended for use on the wiper board.  Oiling with comm drops or any other oil is NOT required nor is it recommended. Applying any kind of oil to the wiper board CAN cause problems. Under normal conditions, any dust on the board will fall or blow away.  Using oil will pool the dirt in the grooves and can start to connect the pads.  If the action is still rough after cleaning and wiping the board with your finger you can place a strip of 2000 grit sandpaper under the wiper button and, with your finger on the back of the wiper button, move the trigger back and forth to polish the bottom of the button.  Although cleaning with sandpaper is possible without disassembling the controller, it is a lot easier performing this with it disassembled.
DO NOT OIL the Wiper Board