I stayed Aria more than three times. Love their service, restaurants, casino and such but City Bar... It was the worst service experience I've ever had.
My SO and I went there after midnight. It was empty except a group of loud college guys sitting in the corner. The waitress walked passed us several times and wouldn't take our order. A sleazy fat guy with four call girls came in - the waitress was being friendly and attentive. She led them to the couch and took their orders. Uhhhhh, really??! We tried to get her attention and she intentionally ignored us again. The bouncer actually told us to leave without telling us why.
We weren't being rude or anything. Just simply trying to get their attention. ;p