Loved staying here!
Diana is really friendly and easy to communicate with. On arrival she gave us a map of the city and gave us tips on where to go etc.
The studio is immaculately clean.
It gets very hot at night (we stayed in August) but a fan is provided so it was bearable!
Had no problems with the wifi.
The shower is good we had no problems with the temperature it was always hot and we both showered twice a day.
It's on the 4th floor but if you are relatively fit this is no problem whatsoever. A small corridor leads to the studio where you have to dip your head but I don't know why people have moaned about this as it's only about 10 metres long!
Best thing about the studio is the location. Walking distance to everything you need to see in Madrid and surrounded by bars and restaurants in a lovely area called Malasana.
You receive 4 keys but Diana explained thoroughly which key is for which door (one to get into the building, two for a door into the corridor, and one for the door into the studio). We had no problems with the keys at all.
We would definitely stay again!