I didn't meet Maria and Jorge in person, but have communicated with Jorge ahead of my trip. He also tried to help me with a special request to split the bill, as I stayed half for work and half for leisure. When I checked in, I was greeted by a friend of Jorge's, who was very helpful in showing me around.
The studio is as described, small, but has everything you need. As it's really central, you are close to the city centre and a lot of museums, but it also means it can get quite noisy. So I definitely support the recommandation made in other reviews to make sure you have earplugs with you.
Unfortunately, there has been some water damage in the bathroom, which currently results in bits and pieces from the ceiling falling down into the shower every now and then.