If you can stay for less than $100/night, then this hotel is fine. There's nothing disgusting or unsafe about. However, if you are looking for a nice place to stay for $100 or more per night, I would choose somewhere else.
First, on Tuesday night around 9 p.m., I called for a wake up call and no one answered. I hung up and kept calling back every 15 minutes with the same results. After an hour of trying, I called every number I could find -- front desk, conceirge, housekeeping, room service, etc. and NO ONE answered the phone. This was very frustrating. (However, I was able to place a wake up call request on the other nights of my stay) Second, I wouldn't rely solely on the wake-up call. It wouldn't ever be right at the specified time.
Third, the street noise was extremely loud. I heard sirens and construction noise all day and night the entire week. As I was checking out, a colleague told me there are floor vents that are left open, but if you close them, it quiets the noise significantly. I wish I had been told I could close those vents (or if those vents had been closed in the first place.)
In conclusion, this hotel is fine, but I'd stay somewhere else with all the great hotels San Francisco offers!