Great location- it was a 10 minute walk from the Moscone center and the Metreon. Area felt busy, well lit, and safe to walk most times (I still recommend not walking alone in SF), and there was a Walgreens right next door in case I needed anything. Check-in was in another building up the street, and that was a breeze. The building I was in felt very secure as it requires a key to enter.
The room itself was clean but you can tell it's old. The floors are a bit uneven, like the building is slowly sinking. The windows do not have screens, and the elevator makes some strange noises toward the upper floors (my room was on the top floor), so it took a few times before I felt safe using it.
Be aware that if you want your room serviced, there's an extra fee. I believe you can also discuss it with them upon booking. I was confused at first because they leave a "do not disturb" and "please service room" sign in the room.
However, they are happy to replace towels if you ask for them, but I had to go to the building where I checked in - they don't seem to answer facebook messages, the texting number is out of service, and when I tried calling from the phone in the room, I didn't hear back. Communication outside the office could be better.
Check out was as easy as dropping the keys in the dropbox.
Overall, a few things were less than ideal, but out of all the places I've stayed for conferences in the Moscone Center, this has to be my favorite. You can't beat the location. When I needed to unwind after a long day I really enjoyed the quiet and privacy of my room for a price that reasonable. Would stay again!