For the price - excellent overall. This is not a deluxe resort, it's simply a room but excellent views and the basics are there. Elias is an awesome host and makes up for the simplicity of the room.
I would caution that the location is very high up in the mountains and gets very windy at night. And it normally rains in the early evening. Those factors combined, the upstairs room seems to amplify the sounds of the weather through the night. Light sleepers may take issue.
A few other simple things could help improve: a dehumidifier, more hooks for towels. Our shower head was very basic and not pointed straight down but more towards the wall which made showering less comfortable.
All told, if you're here it's because you want to do all the things around Rio Celeste, and you can hardly get any closer to them than here. Plus Elias will arrange almost any of the tours around for a very reasonable price.