Las Vegas is flush with hotels claiming the coveted AAA Five Diamond designation, and the Aria Hotel at City Center is among them. My stay was without question superlative. The Aria has all of the right appointments. The room is filled to the brim with great technology (i.e. the shades are electronic). The gym and pool area are magnificent. There are some great restaurants on property, really enjoyed my meal at American Fish. I'm not a connoisseur of casino floors, but their seems above average as well. All of the staff were attentive, professional and friendly. It's closer to the end of the strip than the middle, but if you go at the right time of year that's barely an impediment.
The Aria was technically probably near perfect. If there's a checklist for determining Five Diamond status I'm sure they received top marks at each category. I have one minor but real complaint. The property is truly massive. Despite the technical perfection, it lacked almost any intimacy. In my experience the best hotels in the world are the ones that comfortably allow you to forget you're staying in a hotel. Though a magnificent hotel, the Aria was clearly just that.