First time I came here, they were barely opening new shops (about 10 yrs ago). The City Center is designed pinky finger fancy. The shops are high end such as Versace, Louis Vuitton, Gucci and Hermès There's a Wolfgang Puck Cucina upstairs, but don't come hungry because that's pretty much all they have. They also have a very nicely designed Starbucks with plenty of seating.
City Center is good for getting your 10,000+ steps especially after having had buffet meals all weekend.
There's a tram on the third floor that takes you to Vdara, Bellagio, Aria and Monte Carlo.