Originally Posted by stanrc
I don't think there's anything to worry about, but it seems like there's always something to be gained from a protune.
Since the OTS maps are kinda one size fits all, they are dialed back compared to a protune in some sense. The OTS maps are not the razor's edge of performance. That said, your biggest limiting factor is the turbo and the fuel injectors/pump. You can only dump so much fuel and air into the engine with the equipment you have. That said, most protunes will make another 10-20hp over the OTS maps and probably that much torque, generally speaking.
Originally Posted by GeneralTsou
I don't question whether you can gain power, but rather can you do so WITHOUT sacrificing reliability
I have never seen a properly tuned car on a stock turbo be less reliable than the stock car. That said, it all depends on how you drive. I have had a customer that was able to burn through clutches, motors and turbos on his stage2 STI on a fairly regular basis because he just drove the living snot out of it. But I would say that the same would be true for the car even without a tune! I also have customers that drive hard eveyrday on OTS tunes, keep up with the maintenance and have years of good hard driving. So, I would say that reliability OTS to Protune is pretty similar given an owner that maintains and takes car of their car.