Ramon's apartment was great. Anyone not able to climb stairs, anyone that is over 5'11" (there is no space to hang your feet off the end of the bed), or anyone who is very large (the bathroom is quite small) might have complaints, but otherwise you will surely love Ramon's place.
The location is fantastic: it is in a wonderful part of the Malasana neighborhood, with excellent bars and restaurants minutes away by foot, yet on a quiet street where you are not being woken up by revelers at four in the morning. It is a short walk to Gran Via, Fuencarral, and Plaza del Sol. The Noviciado metro stop is only 2 blocks away; Tribunal station (for easier airport access) is an easy 8 minute walk. I walked everywhere instead of riding the subway, with the exception of getting to and from the airport. It's a very walkable city!
The apartment is super comfortable. You can hang your clothes in the small closet. There is plenty of space in the living room to write, place books, maps, etc. The kitchen is super functional and well-equipped. The hot water heater easily provides up to a 20 minute shower. The heaters worked very well; I was there during a cold part of the wintertime and had no problem staying warm in the apartment. Being up on the top floor makes the apartment incredibly safe and secure; breaking into the apartment through one of it's windows would be nearly impossible.
I would definitely want to stay at Ramon's apartment again when I return to the amazing city of Madrid!