I came through here twice when I stayed at Aria and both times I came in it was completely dead. As everyone else has already mentioned, all the stores are super high end. The layout (at least on the 2nd floor) doesn't seem to be that conducive for window shopping.
Two stars for the mall itself with an added bonus star for the small James Turrell installation. If you missed the Turrell exhibit at LACMA and the Guggenheim go up to the top floors of the mall to see a few rooms with Turrell installations. It's pretty cool.