We -my son and me - had a nice stay in S. F. The Carlton is located really centrally - and even at night we didn't feel uncomfortable in that area.
Especially the staff was very, very friendly and helpful.
The room was clean and cosy, nice view from our room, nice lobby.
(We had our breakfast only in near restaurants, at night the "Fly" (just beneath the Carlton) can be recommended.)
One thing that was not optimal: We sometimes had little problems with the WLAN/WiFi, but the staff was also very helpful with that and they tried their best ...
We enjoyed the really nice elevators (worldmaps and nice pictures !).
We hope that we will have the opportunity to come and stay here again ...