Mandalay Bay--
Overall, it was ok. Players were average and some LAGs. I didn't like mini-blinds (1-2). Room is comfortable and dealers are decent.

Orleans--
Overall, I thought players were tighter than I would have thought. I played 2-4 before noon tourney--average age at table, not including me, was 65. Lots of little old ladies who were very good players!
The tourney was a multiple rebuy for first hour. This was my first live tourney so I didn't really know how to handle rebuys. It was insane! Some people would go all in almost every hand and bust out then pull out another $20 for more chips. This happened over and over. I had to buy 3 rebuys just to keep up with average stack. I busted out when my pocket kings got beat by flush on river. Finished 38/86. Tourney was well run but no more multiple rebuys tourneys for me.

Imperial Palace--

I played at beginners table right after the 11 am lessons ended for these folks. Thinking I could overtake the table and dominate, well that just didn't happen. Players were loose but I just couldn't hit anything.
Tourney was $55 with 1 rebuy. About 50 players. I got lucky a couple times to make final table with medium stack. With 6 players to go and me being the small stack, I found pocket AA in front of me and I tripled up. I ended up in final two and we agreed to chop. Not bad!

Mirage--

Nice poker room. Players were generally tighter than not but I ended up exactly even after 2 hours of play. I didn't have time to play more.

Bellagio--

The poker room of poker rooms! I sat down at 8 pm
and quality of players were surprisingly loose. A gentleman to my left bet EVERY hand! Unbelieveable! The starting hands for 50% of table
was horrible. Around 10 pm Sammy Farha, Phil Ivey, and Ted Forrest, and others sit down next to my table for $4k-8k holdem. There was over 2 million on table. Watching these guys was the highlight of my trip! Anyway, the drunks arrived at my table around 2 am and I played until 6 am. I had a blast with these guys!

Conclusion:

I agree with AllVegas that Imperial Palace has decent low buy in tourneys. However, I found that overall players everywhere were good players and not as loose as advertised.