This is all very interesting, my v7 sti was tuned by torque performance using an ECUTEK in 2007 to 200kw on 20psi with 825nm of torque, since then it hasn't been back in the dyno at all to my knowledge, I purchased the car and have only done maintenance, and handling / braking upgrades, while in Auckland this week (I live in Wellington) I decided to take it in and put it back on the dyno
they ran data logging which showed no issues, then did a power run, it produced 202kw on 20psi and made 825nm of torque, they said it's as healthy as I could hope for, they said without upgrading turbo, tmic etc i won't gain much and they didn't want to play with the tune as it had proven to be reliable for the last 10 years
so reading all these comments about your bad experiences with them actually surprised me