I personally think 6700 ergonomics are complete crap, so I would rule that out. Force is nice and clicky and if you have a BB30/PF30 frame then go for that, but if not 6800 is nicer. I've run 5700 105, 7900 Dura Ace, and 2012 Red, and shifting is basically all the same so its down to ergonomics at the point and since you're probably going to spend most of your time on the hoods find a shape that fits your hand.