I stayed with Simon (and family) for two weeks. They are very warm and accommodating. Meeting their family was the best part of my stay! They and their two cute dogs were always making my feel welcome.
The room was clean and comfortable. It had all the amenities (large private bath with a huge bathtub [no shower unfortunately], comfortable bed, fully-equipped kitchen, washing machine, high-speed internet, etc.).
The location couldn't be better! It's right outside the Loreto metro stop, in a vibrant neighborhood. There is a supermarket steps from the apartment and tons of restaurants, shopping, etc.
There were a few draw-backs for me. I agree with one of the other reviewers that the house was very clean but the walls in the rented-room were dingy (stained from smoke tar and lots of wear)―it needs a paint job. Otherwise, everything was very clean! Also, Simon smokes in the house (usually just in the kitchen and their bathroom); it's not bad and is fairly contained but you can smell it. This is pretty typical in Italy, and I wasn't surprised, but on two isolated occasions he smoked something more 'recreational', which did bother me.
Overall, my stay was pleasant and I'm very glad to have met Simon and his family. They were really very lovely and made me feel at home.