Please define "most," as in how many cars and where did you see them. I guarantee there haven't been 10 GTs on a dyno outside the factory, and realistically likely not even 5. My car made 576 rwhp, and a black car here did 590 rwhp on a dynojet. Most of the cars at the factory with 2-5 miles do ~570 rwhp on the factory dynojet, in a range of ~550-~590 rwhp. As Brian said, I would expect the "after" numbers here to be pretty close to a generic run-in car.
If you mess with the power output of this engine, just be aware:
You will immediately void your warranty
You will significantly shorten the lifespan of your powertrain
Getrag DCTs are not exceptionally robust at high levels of torque
For people that own a new GT, take my advice or leave it, but there is an extremely high probability some dude selling you a $1500 (or whatever) power upgrade will result in you footing the bill to split your $550k car in half to repair your damaged $40k powertrain.
This may not be a concern for some people. Good luck.
