My family just stayed at the Sheraton for 10 days over Xmas. The location sucks, I wouldn't recommend the (only) hotel beach in Rio where you don't have to cross the street. On the other hand, the dollar is so strong at about 3.5 reals/dollar that taxis are dirt cheap. I felt that generally prices in reals were similar to prices in NY in dollars. So when a car service to the airport was 50 reals, it was about $15. A taxi (cheaper than the car service at about $$4-$5 bucks)to Ipanema beach was about 7 or 8 reals (under $3). So if you're using points, stay there and "splurge" on the taxis. Friends stayed at Caesar Park, and they loved it - the beach is nice there, more crowded (-), but better patrolled and better services (+).

We generally try to avoid hotel mini bars as rip-offs, but at about a buck for a bottled water, who cares. Shopping and food were unbelievably cheap, with "expensive" appetizers for $3, entrees in great restaurants for $10.