The flat is just as described. The photos don't do the amount of space the flat offers justice, with it being much more spacious.
Being located in the very centre of the city, it's very easy to get around (the great thing about central Madrid is that so much of it can be walked). There is a certain level of noise out on the streets for many hours of the day and night, but that just comes with being located in the centre of Madrid, which is always a lively place. :-)
At present there is a construction site opposite the building, which does lead to some noise in the mornings for the person staying in the bedroom upstairs, but no construction site lasts forever.
Be prepared (as indicated) to climb a lot of stairs to get to the flat, which leads to a bout of exercise every day.
Communication with Oscar was easy and he was very responsive and attentive.
Definitely a flat worth staying at again.