This place is a room in a hotel. The room was very spacious, perfectly clean, and had a number of amenities (microwave, fridge, coffee maker, safe). Check in and check out were both very efficient and pleasant. The location near Union Square and Market St is a great base to explore SF (close to BART and lots of express buses). The only drawback of the room is that it's not super charming, but that's not what I was looking for. The location can be a bit unpleasant to walk around because it's relatively close to Civic Center. The room I got (at the corner of Mason and Post) was somewhat noisy because it was on a lower floor. Most other rooms probably wouldn't be.
I'd rebook when visiting SF in a heartbeat.