Things to like about Rio.

Large rooms with minibars, fridges, coffeemakers, huge tubs.
Fast, reasonably priced room service.
Huge pools (but they are quite distant from your room).
2 buffets, one seafood.
Lucky Strike bowling lanes.
Gaylord's Indian restaurant.
Chinese menu in coffee shop.
The Diamond Lounge & other Diamond perks.
Chippendale's
Penn & Teller

Quirks:
Few blackjack (3/2 not single deck 6/5) tables. Lots of empty 6/5 tables.
Minimum craps bet usually $15 even when uncrowded.