Ruben's place is perfectly located if you want to stay in the Centro Historico. The apartment is spacious, and the room is comfortable (bed is for one person). It is quite tranquil and relatively quiet for being so central. It is an older building so you hear some noise from neighbours, but nothing at all disturbing.
Ruben has his studio in the apartment where you can see his theatre mask-work, and he is a very pleasant person to talk to. Very laid-back, and available for any issues or questions.
The apartment is very clean and comfortable. Good hot water (after waiting a few minutes) in the shower. The only small problem is mosquitoes at night, but only for a couple of hours. Otherwise, a restful and pleasant place to stay, good value. Recommended!