I would have 3 bet the turn (since MP1 already called) and bet out the river . . . but since UTG player is very aggro (and MP1 such a calling station) I think the river check raise worked out for you (but it won't always). I would just take their money on the turn and bet out the river.

Were you fearing trip Q and the possibility of the full boat? Were you afraid that someone had the A [img]/images/graemlins/diamond.gif[/img]? Then decided to C/R once a 4th diamond didn't hit? Don't be afraid of your opponents!! . . . your edge is too big!! RAISE!!! =)