World Superbike Racer
Join Date: Apr 2015
I Ride: 2015 30th anniversary ZX-6R
You are juggling chain-saws. I would go back and take close-up photos. Bring a rear stand and have the owner hoist it up for you. Check to see if the wheels track true. A frame can be tweaked with only a slight kink to it and handle like shit. I've seen happen to bikes that were dropped by their owners in their driveway.
Study the photos you take, re-examine these with a magnifying glass. The owner of the green '11 might just be a squid with the graphic kit, but it devalues the bike when you go to sell it. You can use that as a bargaining chip.
The reality is if you are drawn to one bike over the other, than that's the one to buy. Neither bike is a 'gimme', each is fairly priced, but neither is a super "buy."
Part of the true answer lies within your own personality, are you OCD about the 'little stuff,' if so, buy the one that's in the most OEM condition. Personally, I'm a twisted SOB, and cannot abide owning a 'stocker', I insist that my bike is unique... "I want to remake it into my own image." Yet, I know I'll never recoup my investment. That's perfectly OK, 'cuz I don't ever plan on selling it. I'll ride it as a 'modified' bike until 1 of 2 scenarios plays out: if it gets wrecked, I'll simply rebuild it again, but differently - trying out different components. Or, the other alternative is I'll turn it into a dedicated 'track bike' that never again turns a wheel on public roads. BTW, this latter option is not a stretch from its current morphology.
So, one has to figure out "what kind of cat" they are. That's either your starting point - a blank canvas, or... it really is your end point - you are only going to perform the bare minimum to keep it road worthy - O.E. is perfectly OK with you. Neither is intrinsically right/wrong, good/bad... It's what fits you. Good luck hunting.