The problem is that GM has marketed the C7 Z06 as a 650hp car, but has hidden the fact that after X amount of time, due to emissions and safety, the car pulls timing and derates from the advertised power level and the only way to avoid that is the have an aftermarket tune.
Some people are starting to call for a class action lawsuit against GM for it, ala the 99 Cobra. Jalopnik has gotten ahold the story...
http://jalopnik.com/2015-corvette-z0...-to-1669754727
If the ECU is pulling power until after the break in..then GM needs to disclose that NOW. Not later, not after pressure, NOW.