Small rooms, great price, excellent location, friendly staff
My wife and I spent a week at the Club Quarters in San Francisco recently. We will return. The rooms are a bit small but we spend little time in our room Bed was comfortable, bathroom big enough and the unlimited supply of water (bottle it yourself) on each floor is a good touch and a cost savings for those of us that go through 3 or 4 a day. 
The restaurant next door provides breakfast and their are many excellent places to eat nearby. It's within walking distance to the Ferry Building, cable cars, Chinatown, etc.