Very nice place, the apartment was really spacious and clean. The beds are quite comfy although some of the them have spring mattress.
It is a bit far from the center to walk there, but a combination of bus 80 (just on the other side of the road) and metro will take you to the center in 15 min.
I must say that it can be a bit noisy at night, there is big street under the (old) windows, but it didn't prevent us from getting a good sleep.
Paola was really nice, she was there waiting for us when we arrive and explained us all we needed to know, from how to get to center, to where was the closes supermarket (just in front)
In general I recommend the place if you want to find something with a very good value for money ratio!