Was in town for an overnight and all day meetings, caught the BART from SFO and walked to the W.
First, the W's reception lobby seems strangely located, you go through the revolving doors into... the bar? Wander down past the bar and in what looks like a large hallway is the reception area. The staff is truly friendly and provide great service.
Was given and upgrade to a high floor corner room (thanks SPG!) that was very large, had great views looking out to Market Street facing side. The room was clean, bed was great and had an enormous bathroom, somehow that standard tub/shower seemed a bit out of place in this room.
Elements of the room were showing some mileage, bits of the desk were missing/broken, and in general some painted areas were scuffed/dented.
However, it's a great location if you're attending a conference at Moscone or visiting SF, eg. the art museum is right next door and you're just off Market Street and can catch the street cars or the BART.
hotel reviews