I actually met and hung out with 2 McLaren corporate guys at the Amelia Concours about 2 weeks ago. Great and cool guys. One guy is one of their top engineers. After a drink or two, he pretty much said the 650s has some slightly different front trim and only about 35 hp more than the 12c - a mere 5% bump. Unnoticeable performance difference to 99.9% of folks. The 12C will, and has depreciated because of it, which makes it, as W.Mitty said, the performance bargain of the decade. If only I had more time...