What a great tribute to the classic American Musical Theater! Incredible talent, amazing orchestra (and full orchestra at that - no half pre-recorded or sequenced keyboards). The set is pretty amazing as well.
My only (minor) beef was it was too short. Only 70 minutes? Needs a couple more numbers to at least make it 80. I also agree with another Yelper who mentioned Steve's voice over in the show. I would have rather had one of the 4 main performers come out and share that information. I know it's covering costume changes and all that, but you've spent all the money on a great live orchestra - have them play a little ditty or something to fill time. Musicians love to ham it up (well, strings usually don't, but brass players do).
Since the show's only been running for 2 weeks when I saw it, I'm sure they are still tweaking the flow a little bit. If I hear they've changed it up a little, I'll definitely see it again next time I'm in Vegas.