I stayed at Mario's for 2 weeks, while in Valencia for work.
I was able to work from home easily when needed.
Apartment is spacious, and clean. All other housemates I met were very friendly, as was Mario when he was there.
Bed comfortable. I had everything thing I needed for a great stay. I'd thoroughly recommend.
The apartment is on the 4th floor, and no elevator. No problem to walk but an FYI for those with accessibility considerations.