We spent 4 nights in this very handy, accessible and confortable appartement, on a very very busy weekend in Madrid, and no noise was coming from the street !
Carmen and her husband are very kind, very reactive and helpful, and they provided everything very well.
We were 2 couples and 3 babies, and it was OK: enough space for 3baby beds (that we brought ourselves) and trolleys (small ones, though). Few stairs, few noise, and few light of the day also but the idea was to spend the days out, so it was ok.
We really recommend this location to you! Enjoy