Happy birthday, oh friend who can now LEGALLY look at HENTAI! (IF you wanna).
Yeah, I think that's really the only real difference besides Voting (also mentioned above). Now he can Legally by anything a normal person can but Alcohol (and I didn't want/care about that anyway then or now in my own case...).
However what you've all missed.
NOW he can attend the 'late evening' events at Kumoricon.
Also, he can apply for a staff level position.