I've had one for about 8 months now in my 24gal, and he's been doing great. I used to see him more, before I got a new Peppermint Shrimp (after the other one croaked), but he still lurks around. I've only had 1 problem with him, and that was when he zinged a curious Flame Angel in the mouth (wasn't my fish, just babysitting).
I actually thought I lost him twice, because when he molts it usually comes off whole, so it looks like his corpse is floating along the bottom!
When he is out and around, I love to watch him react to the fish around him, the way he waves his 'nems around at them, and kind of does a 'Haaaaay.... hooooo...... haaaay.....hooooo" arm wave when he's trying to catch food out of the current.
I've found that mine doesn't like target feeding, he's way independant. What surprised me was that he'll use his 'nems to pick stuff up off of the ground, not just out of the current. He'll even eat drifting bits of algea (but not pick it right off of the reef!).
All in all, I really dig mine, he looks cool, and is fun to watch. And the best part: he isn't a problem! I highly recomend one.
PS: pmake sure your tank ins't an aggressive one.