The base calipers are just as good as the 14 Brembo's. You won't gain anything from this swap other than a brembo logo. I'm not sure they will bolt up either...2014 had 15" rotors and the 2016 base is 15" rotors, so use 2014 Brembo calipers and no need to change a bunch of stuff. Plus I know of a pair of new 2014 calipers are.
Plus I want to use the spare tire.
The only ones that I'm aware of being 15" where the gt500 brakes, which look similar to the PP GT brakes.2014 and the 2015 base gt never had 15" rotors only PP GT.