This is a really nice and very safe place to stay. They have a big common kitchen at the ground floor which is cleaned regularly.
Also, you would find many people staying there for months and very satisfied with the overall arrangements.
The best part is that most of the downtown areas are at a walkable distance (15 mins).
The only drawback is that rooms might feel small for 2 people but I guess, this is valid for whole of San Francisco.
Nonetheless, you would not regret this.
Go ahead.