Here is Car & Driver's 2013 to 2015 Test Data for the GT
Call me crazy, but a lot of those numbers for the 2015 seem to be better. That's why I still don't understand why there's so much doom and gloom based on the reviews, especially considering there's no track data (which is where this car is supposed to be most improved over the outgoing model).
Current: 2014 V6 Mustang Premium, Automatic Transmission, Oxford White, Safety & Security Package.
Previous: 2006 Chevrolet Cobalt LS, bone-stock except for automatic transmission.