Spark -- there have been several discussions of the Rio over the past two weeks that you may
want to look up.  Here is what I posted to a similar question...I have made the Rio my home casino
in Vegas over the past 5-6 years.  My only addition to my review below is that while the rooms are
still very nice, you do need to remember that their standard room is a 600 sq. ft single room, not
a "suite" as many of us think about it.  It is still a VERY nice room in my opinion, but if you really
need a traditional two room suite it will cost you more.  IMO, only the Bellagio and the Venetian
have better rooms, and they are usually at twice the price.

Location is fine if you have a car, or want to cab.  I don't walk much in Vegas anyway.  If you have
a car, try to get a room in the Masquerade tower when you check in.  You can then park in the ramp
to the east of the resort and take the walkway into the Masquerade casino.  It will save you some steps
over staying in the older towers (where the rooms are still nice).  I personally love staying at the Rio
since I have such good access to I-15.  I can get to other strip properties or downtown faster than
most people staying on the strip.

Rooms continue to be in the top 3 in Vegas, behind only the Venetian and some Bellagio rooms.
Very large, with in room safes and refrigerators.

Restaurants:

Very good/excellent --
Buzio's for seafood (moderate to expensive)
Antonio's for Italian (expensive to very expensive)
All American Bar and Grill for steaks and burgers (moderate)

Good --
Fiore steakhouse (very good food, just don't like the value)
Bamboleo for Mexican (there is Guadarno's at the Palms which is superior) (choke)
Both buffets (I think both are now overpriced, but the food is still good)

Average/not so good
San Palo -- just a coffee shop.  Good for its genre.
Toscanos

I love the Wine Cellar for wine tasting!

Voodoo lounge has a great view and interesting drinks.  Pricy and not my style, but maybe yours.
Club Rio will bring out a very interesting younger set.  Fun to watch.

Pools are very nice, and drink service is good.  Most tables are $10 minimums and up.
Slots are some of the lower paying in Vegas by most accounts (see www.thewizardofodds.com).
Cocktail waitresses are still top notch.  Service in general used to be out of this world...now with Harrahs
owning it everything has slipped a little IMO.  Sign up for the Total Rewards slot card and check your
balance at the end of every day....I find the club confusing but relatively generous for low-mid play.

Gold Coast directly across the street gives you access to lower limits, lower food prices, and better slot/VP odds.

I like the atmosphere at the Rio, and I get a fair amount of reasonable offers from them.
I am not a big player by any means.  I've always found the staff friendly and have always had a very nice stay.