I've stayed a the Rio a few times over the years and I must say the newly remodeled suites are good. The rooms were not the best when it came to details in the corners or floors, but I'm only there to sleep and wasn't expecting a top tier room. Since I come for a convention, my rooms were also discounted and resort fees were waived.
The Casino has all the regular tables and slot machines, but it has that old 80's/90's feel to it. Not like the newer Wynn/Encore or Cosmo.
The Rio hosts Chippendales and Penn & Teller. The have a few restaurants and places to get cheap eats. I love going to the Hash House for breakfast. They have massive portions. The All American is good too.
Overall, the Rio is a great place to stay if your convention is in the hotel, but if you want to be close to the action stay somewhere right on the strip.