We just stayed for a week at Marie's flat and enjoyed our time there. The location is quiet, tucked away in Nob Hill from the bustle of Union Square, Polk St, Chinatown and Fisherman's Wharf, but easily accessible to all. Located up on a hill, it may be a challenge for some to return to at the end of the day, but one isn't left too far from lovely vistas of the city or across the Bay. There are a couple of small markets within a block; a Trader Joe's and CVS also nearby; and a coffee shop and great place for brunch (Mymy cafe) as well.
The flat itself was comfortable for two people for relaxing after a day out. We were able to work from there during the week, with very fast wifi.
While we never met in person, Marie was thoughtful and communicative, and checked on us after check-in and just before check-out.