Ruben's place is located in the heart of the Historico Centro. Lots of great places, like the Zocalo and Belle Artes are within easy walking distance. Ruben was an attentive host and made sure to be available when I checked in - even though my cab ride was significantly delayed due to heavy traffic. I had an early departure the following morning and Ruben was there to see me off and collect the keys.
My private room was clean, however, actual privacy was limited as there is no lock on the door itself. There is a large window in the room that lets in lots of natural light. Unfortunately, the curtains on that window are very sheer letting in too much ambient light at nighttime for restful sleep. The mattress is uncomfortably firm as was pointed out by a previous review (and I like a firm mattress!). The bathroom's shower is in an antique claw-foot tub, yet there was not a shower curtain. This means a wet bathroom floor and water that must be squeeged into the floor drain.
The kitchen is more than adequate if you want to prepare meals with plenty of fridge space. I rated Ruben's place 4 on a scale of 5. A few small improvements to the room (a door lock for a truly "private" room, better curtains and a reasonably comfortable mattress) along with a shower curtain around the tub would move my rating to 5 out of 5.