This is a rough one. I may like the ride of the 770 a little better; it's super quick and the handling is twitchy. It's more of a crit racer. The 759 is a little more relaxed and predictable, while still being a fast one. More a speedy all day rider.
Greatly prefer the aesthetics of the 759. It's a classic, for sure.
I'd have to have both.