Not that I would, but the guy down the zorst shop said that de-cat would end up robbing the car of low end torque, if all else left standard.
If so then I'd guess the same could be said for a high flow cat.
They should know their zorsts, but I doubt they really know their GTRs......
I wonder where the truth lies? Probably down with my tuner at $110 per hour.....plus big margins on all exhaust parts supplied....
EDIT, a question. If you put a very free flowing exhaust (however so you choose) on a standard engine and computer would it run rich / lean / get confused at all, or is that all accounted for in the cleverness of the ECU?