I'm starting to think there isn't going to be any real performance gains for 2015, other than a smoother ride and less dive under braking.
2011-2014 BPP/TP cars handle very well, and appear to have the same brakes and wheels/tires as on the 2015 Performance Pack cars. Yes, the revised suspension (front and rear) should help handling, but it could also be off-set by the weight-gain.
Straight-line is going to be a wash. And I don't think the Launch Control will mean much on a MT car. Might make it slower, actually. LC works wonders on DCTs, but I doubt it's usefulness on MT cars. It's not difficult to launch a MT car, so why they think they need LC on them is beyond me.
2012 GT Premium, Brembo PP, MT82, 3.73s, Blk/Blk. Bama 93R, Koni Yellow Rear Shocks, Hawk Ceramic pads, Luxurious & Plush Floor Mats