If it made it this far and isn't noisy, it's one of the good ones. People way blow this out of proportion and I am actually one of the unlucky few that had serious problems with mine so, you'd expect me to be a hostile witness.
My advice is to stretch a bit and get a 13-14. They are much better than the 11-12 cars in terms of incremental development and have higher value, being not first year and newer.
I've had 5 Mustangs, 2 of them S197s, a 2012 BBP and a 2014 BBP I have currently so, my comparison is based on real experience between the 11-12 and 13-14. Frankly, I like my cars loaded up with bells and whistles, especially American cars, that tend to the cheap inside so, I'd recommend looking for a set of options you really want and don't compromise.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto tune, 100 shot on BBR tune, best et: 11.38 at 120.85
2012 GT, Candy Red, Brembo, 3.73, Tech, Comfort, etc. Procal tune, Roush upper, UMI LCAs, Steeda red bracket, GT500s, 28X10X16 Hoosier slicks, best et: 11.91 at 115.23 RIP