Good location, typical Westin, nothing out of the ordinary
We were beginning a four week tour of Africa and China by celebrating a birthday in San Francisco. We had flown in from Portland, Oregon and were catching our Cathay Pacific flight out of SFO the next day. Being a Starwood Rewards member we booked a room at the Westin San Francisco Market Street for the night. Also being a Hilton Honors Diamond member I was expecting a less than ordinary welcome and possibly something special considering I had informed them of the nature of our stay. We got nothing! Not that I was expecting much, but even a piece of chocolate and a "Happy Birthday" message would have been appreciated.
We were given a $15 drink credit at the bar, which pretty much afforded us one glass of "cheap" wine. 
All in all, this hotel is okay if you need a quick place to stay in San Francisco. Do not expect anything above the ordinary, and if you are a Starwood member, consider switching to Hilton Honors. At least you would get an upgrade if available.