We stayed here for 5 nights at the end of Feb and found the hotel to be a good choice.

The Atlantis is nothing spectacular but then it does not claim to be and it does all the basics satisfactorily at a good price and in an excellent location. It would be very unfair to expect 5 star quality at what is very much 2 or 3 star prices by Rio standards.

The room was a reasonable size (photos in earlier reviews are a very fair representaion), clean and comfortable. The rooftop pool is small but nice to have, although not a huge draw, especially given the proximity of both Ipanema and Copcacabana beaches (both 5-10 mins walk).

The breakfast is average and the front desk staff are only OK and their somewhat brusque manner could be improved.

Having spent a lot of time trying to find an acceptable quality hotel in a good location in Rio without breaking the bank, we feel that the Atlantis Copacabana really did deliver in what is undoubtedly an overpriced city for hotels

We read reviews on TripAdvisor and also a guide book and were sorely disspointed. It seems from reading reviews it is very much about particular rooms. We got a fairly big room but it had two single beds even though we had asked for a double. No problem - they came and pushed the beds together! The air con didn't work. No problem - 3 guys came and replaced the whole unit! Eventually we had a room. This place is basic and there are much better 'basic' places in the Rio beach area. Shop around.

We paid almost $100 per night. We were assigned to room number 405. It was the most awful room i have ever seen in my life. Very small, the bed was impossible for 2, with view to a wall, the a/c very close to the bed and very noisy. We inmediatly asked them to be changed. They changed us only the second night to room 308.This room was much bigger than the first and the bed was OK for 2 people. Still the a/c was very noisy and the TV was extremely small. The breakfast was ok but not a big thing.
They then explained to us that rooms ended in 5 or 6 were smaller than the others and only recommendable for people staying a few days. I do not believe those rooms are recommendable at all.
Location is good.

Atlantis Copacabana is a very nice hotel. My room was $80.00 per night and I was there for 9 days. What I loved most about the hotel, was the location. Beautiful block, easy walking distance to Ipanema and Copacabana. On a previous trip, I stayed at the Martinique Copa. Beautiful hotel, great breakfast, okay location.
What I did not like about the Atlantis Copacabana, is it could use a little repair. Furniture gets a little old and some things in the room need to be fixed. A little more attention to detail. . Their breakfast was just okay, and I thought the front desk people need to have a nicer attitude towards their guests.
That being said, Atlantis Copacabana offers a lovely stay in Rio de Janeiro.