Hi,
i am back from Madrid and i have stayed at that apartment in Hostal Jaen and loved it:-)
The location of the apartment (calle Cervantes) was just perfect, close to everything and very centrally located but the street was very calm and it was not noisy at night.
The apartment was clean and spacious, well probably even a little too big for us 2 people. Would have been perfect for 3-4 people although can house more.
The hosts were also nice people although we didn't see much of them since the apartment is located on the 4th floor and the hostal on the 3rd.
We liked it a lot and recommend it. In one of the previous posts i read a complain about air-conditioner. It was not very hot in Madrid but i did try that airconditioner and it worked perfectly and silently. And it looked like a new one too, so probably it had been reinstalled.
Thanks for people recommending it to me