Spacious, great location, helpful host.
For example: One of my family members has asthma, and Mark was very helpful, allowing me to inspect the apartment before reserving it (I was already in town), so that I could make sure there were no asthma triggers. It's good (no perfumed laundry smells, for example). (On the second day, I eventually noticed that the sofa in the living room is a little dusty, and the drapes are a little dusty, but it wasn't too bad. Perhaps a little more attention to dust would be helpful.)