This place is wonderful. Very large, clean, and AC air conditioning worked wonderfully. The location is also pretty good, with several places to eat around the corner and a many many places to eat within a 10 minute walk. Also very close to Plaza Mayor. For anyone wondering about the double bed, each of them are about 3 feet wide (I think collectively the joined bed is almost a king sized) so you're not going to feel like you don't have a room on either side.
My only minor complaint is that the walls are pretty thin. I had no issue with noise from neighbors at night which is where is actually matters but I was able to hear them prety well during a few hours in the middle of the day. Not a huge deal as I'm not trying to sleep at that time so it wasnt too annoying.
Speaking of noise, there was no outside noise late at night, which i heard is a common problem in parts of madrid.