The only problems the Stage 1 ever had was for the '03 GT. It was a computer glitch that would make the PT overheat. That was very early on when the kit first came out. There have been no other problems with Stage 1 at all, either for the PT turbo or the SRT-4. I had no problems with Stage 1 on my '03 GT or with Stage 1 or Stage 2 on my '05 SRT-4.
As for install, on the pcm there are four bolts. If you can use a rachet you can do this. The four cables unlock with a red sliding plastic tab and the cables come off easily. The auto tranny learn is so easy a beginning driver can do it. If you go to the dealer for the install they'll charge you around $200 for install and tranny learn. For them it's a 20-30 minute process. If you want to spend the money, though, then go for it. Stage 1 will put a huge smile on your face.
