I was in Madrid for a two night break in Madrid with two other friends and we loved Dani's apartment. The location couldn't be better - in a really cool neighbourhood full of nice restaurants, bars and independent shops but it's also close to all the main attractions - usually within 30 minute walking distances.
The apartment was stylish and good size for 3 people. The rooftop in particular is great.
There was a problem with the fridge making a noise, but Dani responded quickly to our messages. In fact he was generally quite easy to contact, in the lead up and during the visit.
There is also a lift in the building, which is useful for taking up luggage.
Would definitely go back!