We stayed at the Vdara Hotel, which is part of the new City Center complex beside the Bellagio. There is also the Aria Hotel and Casino, the Crystals Mall, and the Mandarin Hotel. I was quite impressed with the design of the complex, especially our hotel. It was very "artsy" and very welcoming. Without a casino, the Vdara is a "boutique hotel", and the room was spacious, with a kitchenette, dining table and large "main room". The washroom had both a tub and shower. The big problem was the door would not shut properly and every time I had to manually close it rather than let it automatically close on its own.
The Aria Casino was not one of the best casinos I've visited in Vegas. It was a bit dark (not as dark as the Mirage) and unwelcoming. But the layout was pretty good.
Overall I liked where I stayed at. As said before, it was quite convenient as the Bellagio was just next door.