Great location, great price. I stayed here for one night before a conference at the Moscone Center. Check-in was very easy, and my room was perfectly comfortable and clean. I was expecting a hostel, but I felt it was more like a hotel.
The only issue I had - which others have mentioned - is the noise. Noise (and construction!) from the street and from outside my door made it difficult to sleep. I'd recommend bringing earplugs.
Still, though, the place is a fantastic value and in a wonderful location. If the noise doesn't bother you, this is probably one of the best values in this area.