We had a great stay here. The views where amazing and George and his friend were very helpful. You will see boys walking around babilonia with guns and walkie talkies so its not for the faint hearted! Having said that we stayed 5 nights in Rio in the Santa Teresa/ Lapa area and felt more unsafe there because of the huge number of homeless there and the dirtiness of the area. Babilonia/ Leme is quite clean and the people are friendly.
A downside to the apartment is that you have to carry food and water up many stairs. Also, are no mirrors in the apartment (just one outside, which has seen better days!) so applying sunscreen/makeup or bushing teeth might be a bit of a problem and there is no microwave either. Just 2 pans for cooking.