The Palms is much more generous than the RIO. Games are lower limits and staff much friendlier. You can request a non-smoking table if desired and the overall atmosphere is much better, positive than the RIO.
when you say, ALL the games. For instance, Bellagio still has decent (not great) BJ, even though it is under the MGM Mirage umbrella. Harrah's and their casinos have sucked for many months, if not years.
Given the financial issues at Harrah's in general, and the Rio specifically, the Palms is somewhat better. Both have decent games, but the minimums are marginally less at the Palms for the same level of comps. The suites are slightly better at the Rio though, and the Rio buffets and restaurants are better, although the Palms definitely is trying hard. The Palms mexican restaurant is better than the one at the Rio, but the other restaurants at the Palms are marginally poorer than the Rio, and there is no restaurant that can compare to either Buzio's or Voodoo Cafe.
Both casinos are actively barring counters, so camouflague is a necessity at $50 per hand and up.