Is Limping UTG w/ AA Bad?

I've been clearing the Bet365 bonus playing 1/2. I've noticed as a whole the games have been very tight/passive. I'd just assume its because there are a bunch of bonus whores there. Twice before I've picked up AA either UTG or UTG+1, and I've raised, only to have everyone fold. I saw a guy limp with aces and take quite a nice pot off the unsupsecting BB a few days ago, so I figured I'd give it a try.
This is my first orbit at the table, and I don't recognize anyone so I don't have any reads. I have no idea how to get the hand histories from Prima sites, but I'll work on it.

10 handed 1/2 Prima Network

Hero- UTG, black aces, call.
4 limpers
one off the button raises, button folds, SB call, BB folds
Hero-3 bets, all limpers fold, raiser and SB call

flop
AQ9 rainbow
check, hero bets, call, call
turn- 7 completing rainbow
check, bet, call, call
river- 2
check, bet, fold, call


Sorry if it is a little confusing, like I said I'll try to get the hand history. Obviously I got exactly what I wanted preflop, a bunch of limpers, a raiser, and a caller. All other streets were good for me I think. I flopped top set, and had two along for the ride.

I'm looking for feedback, especially preflop. Obviously limping/reraising worked well, but its only result oriented. In this specific case I built up a huge pot and got some help on the flop. However, I won't always get a raiser, which then allows me to thin the field. I also won't always flop top set.

Thanks for your advice.