Yes, the dueling pianists are great, but the cover isn't.
To experience the entire ambiance without the price or the effort of trying to jam yourself into the sweaty mob, the easiest thing to do is to head into the pizza place adjacent to it, get a couple slices of your favorite pie, grab a few beers from the vendor on the corner, and score an outside table from where you can look right in (you'll be less than ten feet from the piano). It works best if you have two or more folks, so if you're flying solo in vegas I'd suggest you get the hooker you're with to get the drinks - she may get them for free, and at least that way you won't have to worry about passers-by chatting her up and scoring your vantage point!