As best as I can tell (and maybe I'm just missing the fine print somewhere), the base models probably ship with something like a i5-4278U? They might actually

As best as I can tell (and maybe I'm just missing the fine print somewhere), the base models probably ship with something like a i5-4278U? They might actually be shipping with some variety of a generation 3 i5? I dunno. The Air's seem to ship with a i5-4260U. Assuming I'm at least in the ballpark, if you are pushing the limits of the computer, you'll probably get a noticeably better performance out of the Pro. If you are just doing day-to-day things, it'll probably be negligible.