The apartment was lovely, clean and in a really central part of Madrid city centre. We could walk to all the main attractions and the main areas for great food and nightlife.
The apartment had a main double bedroom and a mezzanine area with two single beds. The mezzanine is not very high and you can't stand up fully on the mezzanine, so you need to crawl along the floor to get into bed. We didn't mind this but it might not be ideal if you are very tall or old.
The kitchen and sitting area are lovely and cosy and the bathroom is a good size with a nice shower. The location is the real winner for this apartment and I'd be happy to stay there again if in Madrid.