I just loaded the Stage 1 tune and am thoroughly impressed with the tune and Evolve.
While I haven't dyno'd the car, the gains are very noticeable, and the car just feels eager to go. There is an appreciable increase in power available in the low and midrange, so you don't feel like you have to wait for it to kick in. Installation was also very intuitive.
Sal offered great communication throughout the process, and instilled confidence that my car is in good hands.
I can't speak for any of the other tunes on the market, but I wholeheartedly recommend Evolve.