On this flop vs UTG raise, I have to think good A or high pocket pair. I would lead flop, if raised I smooth-call, then c/r turn, lead river. I wouldn't worry too much about A's full on this board as he would have to have an unlikely A4, A8, or A9. I say this is a great place to get in as many bets as possible. If he has a high pocket pair he may call to river, which is fine too.