I've had the USshift controller in the wagon for about 10 months and it is working great. Only minor complaint is the small screen is impossible for me to read while driving, but I'm only trying to satisfy my curiosity since all the inputs are done on my laptop prior to firing up the engine. Controller is for a heavily modified 4L80e in a '65 Catalina Safari wagon with a stroker 496 Pontiac engine that started life as a 455. Plenty of horsepower and torque and shifts are set for 6,000 with both hands on the steering wheel. Downshifting was probably the most challenging setup but we found the magic inputs on our own without harassing the techs. Have only read about other manufacturer's units so don't know if we picked the best one - but no complaints with the USshift controller.