The apartment is quite new, central, in an area with lots of pubs and restaurants. Everything is very close so we just walked, there is even a big police station one street away, so we felt safe :). There is also an elevator.
The apartment was clean, the bed is big enough for two people and was also comfortable. There is an AC as well. The windows are quite good, there is not much noise coming from outside so we could sleep just fine. The kitchen has everything you need to cook a proper meal, the fridge is very big. There is even a washing machine, although i don't know where we would have put the clothes to dry, as there is no clothes rack or balcony available. All in all a very nice apartment and we had a lovely time in Madrid! The host was polite and helpful.