My friends and I went with our wives/girlfriends/non-poker players. We managed to stay in pretty close contact with them on a Saturday night as we played in the poker room and the non-players partied in Centrifuge, a bar that is adjacent to the room. You can get up and leave for a max of 45 minutes and still keep your money on the table and seat reserved, so you can theoretically go in and have a few drinks with friends at Centrifuge. I didn't do that, but by all means, drink up... :) I too am not a fan of the marble around the felt. Every so often there would be a player at the table who dragged his cards off of the felt and onto the marble, and I would misjudge how many people were still in a hand.
Mixed bag. I played only $1-2NL. Some rocks, some tight-weak, some loose-aggressive, and some really lucky chasers. I sat down with one drunk tourist who unfortunately had no bills bigger than $20s by the time I made the table. Lots of college kids or 20-somethings, and people who learned how to play poker by watching The Travel Channel and ESPN (asking stupid questions like "do you want me to call?" and wearing sunglasses). Some locals/prop players in there too. Most people were pleasant enough and the action was pretty good - if you're a decent player and can play with discipline (i.e. don't butt heads with the players you recognize are better than you are) you should make out alright over the long haul at the MGM Grand.
I saw some of the other reviews of dealers being inexperienced and slow to some extent, but I didn't see any of that. Most were very efficient and I had played enough hours to sit with almost all of them multiple times. A guy named Devon stood out - the quickest dealer I had seen in my three days there.
Cocktail waitresses seemed to be there whenever you needed them, though at night they were much less frequent. No worries - if you needed a drink, just ask the dealer and he/she will summon the waitress.
The electronic board is great. Everything seemed well organized.
Not much to compare things to here as I haven't played in other LV casinos.
