Mine is a medium. Though I'm just a shade over 5'5". I'm very leggy. Probably part of the problem.

Maybe a good way to think about it is when you are on the hoods, how far out in front should your hands be in relation to your shoulders? Of course, I'm talking in the saddle. I feel like my hands are way out there. Probably isn't as extreme as I feel.

The guys at my LBS are very nice and when I want something, they jump on it. Of course I've got the want to do it myself bug too.