Very clean, great location, but no communal area.
A lot of previous reviews complain about the noise. My room was on the 2nd floor (the music studio is in the basement) and the noise was not an issue. And it did stop promptly at 11:15.The staff was very helpful and the facilities were extremely clean. The major downside, as others have mentioned, is that there isn't a communal area to meet the other travelers. Re: security, it was a non-issue -- there are homeless people around, but that's just how it is in San Fran, and it's not dangerous.