Both my older sister and I skipped second grade.
It was truly, honestly never ever an issue for me. I was average sized, on the shorter size (I'm 5'3" as am adult), neither the shortest nor tallest before or after the skip. Age wasn't a problem -- the only time it really came up was in foreign language class (when we learned to say our ages) and occasionally at birthday time. I have a March birthday in a September cutoff state, so I was already young for grade, but it wasn't an issue. I had friends in my grade, and friends older than me, but kids in my "regular" grade seemed painfully young--I rarely ever socialized with kids in the grades below me.
I got my drivers license at the end of my junior year -- just got friends to drive me around until then. Went to college at 17 and had no problems there. I started dating at 15, as a sophomore, but was interested as a 13yo freshman. I don't think the skip had much effect on my behavior in that respect. I made my fair share of missteps like any teenager; I just had an extra year to make up for them.
In retrospect, I needed more acceleration, but the year I had certainly helped. I was much better placed after the skip than before. The teacher whose class I skipped into was against the idea to start but she quickly saw that I was ready for the move, and she changed her mind quickly.
I have a PG+ cousin who was given subject acceleration but no outright skips. He got to our state's flagship university and completely floundered -- he had no idea how to study, regulate his time, etc. In retrospect, he says, he'd rather have tried acceleration to try for more real peers, apripriate work, etc. That's an anecdote, but a real-live one.
Good luck. It's a completely individual call, and your milage may vary.
