Check out the room listings on
www.allvegaspoker.com. There's a tab just for tournament listings - you can get a snapshot of everything going on in one place.
Aria is listed as one of the best in Vegas. I like to play there also.
I was going to suggest this same site, as it has been about 90% accurate in the past for me, and certainly helps you figure out where the games are, and at what times, so you can plan your itinerary accordingly. lol I would also advise that you call the poker room(s) where you will play MTT's, just to be sure that they still offer a said MTT. As Vegas
casinos are competing for patrons (and the poker rooms are no different) sometimes tournament times get moved up or bumped back, depending on what neighboring casino properties are offering. Also just ask around, while in Vegas. Most dealers are also players, so they usually have info on the juicy games/MTT's in town. Never hurts to ask, as closed mouths don't get fed. Best of luck on your vacation (poker trip.)