The apartment is nice, in a central and strategic position! It's quite small and just as described on photos; this flat fits very well for one or two people, and for a short stay in the city. The apartment is on top floor, and there's no lift, so if you don't have many luggage, it's a really good choice.
Let me just talk about heating: the stove doesn't work well as it shoud, and this could be a problem in winter.
Apart from this the location makes it a perfect apartment to discover and visit Madrid!