Do it. Growing some modest facial hair has made a big difference in being treated like an adult for me. For comparison I'm 30 and if I shave I get carded at movie theaters.
32 here and carded for beer when I shave (at places that normally don't). I guess I don't look quite Under 17 young any more, though, so congrats to you on that. ;)
Now if only I could grow a decent beard...