I really enjoyed my stay at Guilleromo's. I rented a small apartment. It had a livingroom/kitchen with a couch that folds out into a bed, a small bedroom with a double bed, and a bathroom with a shower. I don't think most people would describe it as "charming", but I really liked its classic 1950s rooming house vibe. It's been updated with new flooring, paint, and furniture. Everything was very clean, and the high ceilings make it feel airier than a small apartment usually would. Checkin and access is very easy. Guillermo texted me an entry code that worked on the main entry door and the door to my apartment.
The only negative for me was that the apartment is on the first floor of the building. I would have liked to open the blinds, but felt too exposed to the sidewalk and street. Next time I stay here, I'll get a room on the second floor instead.