I had a great stay at David's. Despite being on one of the best nightlife and dining streets in Madrid, the bedroom is situated at the back of the apartment and was very dark and quiet. I slept like a baby every night.
The rest of the apartment is very cool, with great decoration and plenty of light during the day. There was an issue with the drainage that meant the on suite shower wasn't fully functioning, but the other shower and bathroom was just great anyway.
Highly recommended for anyone wanting to be in the thick of the Malasaña action!