I had a couple of tipped incisors and crowding on the bottom plus a little bit of an underbite - all cosmetic stuff. But at 41 I had 32 teeth which was more than my old man could say.
Overall my treatment went without a hitch. I am atypical among adult patients in that I experienced very little discomfort - the extractions didn't even bother me. The most uncomfortable part of the process was paying the bill

Right now I am in limbo - the braces came off on Monday, the retainers go in on Thursday. Last night -- I chewed gum and it was good.
To everyone thinking about it - just do it! To everyone in the process - tough it out! It is sooooo worth the hassle.
Here are some pics in case you are interested
http://chetter.com/braces