We got in free because someone gave us passes to Liquid (the day club). Once we realized it was $30 per person and provided no advantages we decided not to go in. By that point we were already in the pool area so we just stayed! Sweet loophole (I don't feel bad because it was the front desk's idea).
There are three pools. One was closed. It was fairly crowded but we were able to find five lounge chairs together (in the shade).
Service is great and beers were only $7 each which wasn't bad for a craft beer on draft at a vegas hotel bar (sin city brewing even makes a special IPA just for aria that was pretty good).
Pool was nice and super shallow. Lots of lifeguards for no reason but oh well. You are allowed to brig drinks to the pool and waitresses will take your order poolside. They are very friendly and attentive.
Stopped by jacuzzis on the way out. There are three and they are large.
Come prepared! Sunscreen was $18 and it is sunn and hot.