Good location and friendly easy-going host. Joe's place is a little run-down and not super comfortable for a longer stay for two people, but we knew what we were signing up for - if you're travelling solo or on a budget, this place is clean, quiet and convenient.
Street parking is a mission, if you're staying longer with a car (though at least street cleaning in the area is only every second week, unlike other places in SF). The Richmond is an interesting area, with great groceries and restaurants close by, and the proximity to the Golden Gate Park can't be beat.