Congrats on a killer quant score, BammaBullet! A 680 isn't necessarily going to keep you out of a school that has an average score of 710--roughly half of applicants presumably score lower than a 710, so you'll still have a shot. If your profile is strong enough in other ways, then a 680 might be fine.
But it sounds like you have another 7+ verbal points in you, and it also sounds like you might not be all that happy if you don't at least give it one more shot. At the end of the day, it's a personal call: is the pain of a retake greater than the pain of thinking that you could have done better if you'd given it a second try?
I'm guessing that you'll be able to pull your composite score up if you spend another month or two improving your verbal skills and maintaining your quant skills. Make sure that you really concentrate on avoiding careless errors as you work through more quant practice problems and practice tests--the only thing that could cause you to have a quant letdown is sloppiness. And there's every reason to think that your verbal score could go up with some extra practice. You might also want to spend some time working on your test-taking stamina... lots of full-length tests (or maybe some nasty LSAT CR
and RC sets?) will help you to avoid the jitters at the end of your next verbal section.
Good luck with the decision, but it sounds like you're in a pretty decent spot, whatever you decide.
Helping students kick the GMAT in the nuts since 2002... www.gmatninja.com.