The Othon chain has slipped down the rankings - most are shabby at best, especially in their basic (lowest category) rooms.

Ipanema is generally classier and more secure than Copacabana, the beach next door.

The Ipanema Plaza is a great (smaller) hotel, which really tries hard to please. It's on rua Farme de Amoedo, 100m from the beach in a nice area at the Copacabana-end of Ipanema. There are plenty of other options, but this comes in at the Othon price-range. The hotel has a car service (expensive), but there's a taxi-rank on the square nearby. Buses are easy to use, and you can easily walk to the conference venue.