One of the few differences: The 15" MBP now has a sleekified heat sink with just a single thermal pad, thanks to the more closely integrated GPU—which we attribute to the "Haswellification" process, as we call it.

Another effect of Haswelling your MacBook: This model claims to deliver an extra hour of battery life with the same capacity cells. The more efficient processor likely contributes much to that extra hour of looking at pictures of cats on the internet.