The
RECARO seats in the '15 did it for me and the fact that I will be getting coilovers negated the fact that it was not as stiff as the previous years. A car being stiff is an easy fix. Those RECARO seats are too damn expensive to buy if I didn't get the '15. And lastly, the '15 to me is a more mature sports car and less boy racer without that giant wing. I'm 29 and not a teen anymore.
As far as aerodynamics go, I don't think I will ever be able to push the car hard enough to tell if the aero kit works.