This is a lovely bed and breakfast, and Guillermo is an amazing host! He cooked tasty breakfast every day, provided great advice, even did my laundry. The apartment itself was nice, with powerful air-conditioning and a reasonably comfortable bed.
My main complaint is the excessive amount of dogs in the neighborhood, including 2 at this residence. They bark all night, lots of very loud barking from all sides. Makes it very difficult to sleep, so make sure you bring earplugs! That's not really a knock against this place specifically as it seems to be generally true of the entire city, but the lack of proper windows here means not much sound insulation.
Overall it was a wonderful place and I'd recommend it :-)