How much faster is this car than a bone stock Z? Because for the average owner that's $10,000 in mods minimum.

I've seen the runs, the difference is small. Much smaller than it should be considering the costs involved.

Numbers are whatever you want them to be. My car dynoed 240whp stock at HP logic, was not any slower than a car that dynoed 270whp elsewhere. If the car doesn't actually go faster than another car with less mods, I say that's not a worthwhile gain.