Leblon is the best neighborhood but its polluted beach sucks big time. I was there 2 weeks ago and only ventured into the ocean on the third day, when the brown water turned green, although garbage was still present.

The beach in Barra on the other hand is much cleaner, although not as nice, plus one needs a car to go everywhere as everything is far, and traffic is horrible.

Nevertheless, I'm seriously considering staying at the new beachfront Hyatt on my next trip, as I get very frustrated wanting to go in the ocean in Leblon but can't because it's full of raw sewage which grosses me out.