My gf and I went to the Christmas Eve show and really enjoyed ourselves. I understand the criticism of not having a few more contemporary numbers within the show (something from Phantom, Wicked, or Les Mis, etc), but it did not detract us at all from having a terrific experience. The full orchestra and ensemble had so much energy and talent. The music was great, a great majority of the songs were familiar (and we only have a mild Broadway knowledge), and the dancing and choreography were well done. The cast has clearly put a lot of time and effort into the production.
I've seen a few reviews that are critical of Mr Wynn's voice being heard. Three things: 1. He only speaks three times that I can remember. 2. He only says three or four sentences when he does speak. 3. The show is called Steve Wynn's Showstoppers.
They will surely add to the show and make tweaks as they go to make improvements. All of the lyrics were clear and easy to understand (as opposed to the Smith Center) and the energy was superb.
We had a terrific evening and would recommend the show to others coming to Vegas.