There are a few clutch buffers out there. Except for the ClutchTamer, most are for hydraulic release systems. Here's some links...
...Tilton Flow Control Valve
...Magnus Launch Control Device
...Clutchmasters Flow Control Valve
...ClutchTamer Clutch Slip Controller

Here are the basic differences between the "Magnus Launch Control" , the "Clutch Masters flow Control Valve", and the "ClutchTamer Clutch Slip Controller"...

1- Magnus unit requires "pre-loading" the clutch before launch to make the best of delayed reaction times.
...Clutch Masters also requires "pre-loading" the clutch before launch to make the best of delayed reaction times.
...No pre-loading with the ClutchTamer, and no delayed reaction times.

2- Magnus requires a solenoid bypass to solve it's problem of excessive clutch slip after WOT shifts, resulting in clutch engagement after WOT shifts that's too aggressive.
...Clutch Masters unit has no bypass solenoid, requiring a compromised launch with very little clutch slip to prevent excessive clutch slipping after WOT shifts.
...Clutchtamer strikes a balance between those extremes, creating a happy medium amount of clutch slip after WOT shifts that results in a quicker pass while simultaneously reducing impact on drivetrain components.

3- Magnus solenoid bypass allows quick return of the clutch pedal, meaning each push of the clutch pedal begins at the top of it's travel and includes the deadband travel.
...Clutch Masters unit has some clutch pedal return delay, but with it's compromise setting it's still quick enough that each push of the clutch pedal begins at the top of it's travel and includes the deadband travel.
...ClutchTamer controlled pedal does not have enough time to return to the top before WOT shifts, which effectively shortens pedal travel resulting in quicker WOT shifts.