A quite compact apartment in a very good position, just off the busy plaza where the opera (and opera metro station) is located. We were met at the apartment so check in was fine. Madrid is very lively so the apartment could probably be a bit noisy in summer, in winter with the windows closed and the streets a bit less lively, noise was not an issue. Very easy to get to by arriving at metro Sol or Opera and then a lot of Madrid is walkable from there - for example to Plaza Mayor, the Palace, La Latina etc - all were close by. Check out was similarly easy. We were quite happy there and would probably return for the location and the relatively resonable price. Would be a tight fit for more than two, but for the two of us it was fine.