Powell Hotel GREAT Location!!
We just came back last night from San Francisco and I decided to share our experience!! We didn't know where to stay, so we read reviews and decided the hotel had to be in a great location easy to public transportation. If you are there to explore the city and not to spend all day in the hotel THE POWELL IS THE BEST. You open the door of the hotel you are on Bart(metro that goes to the Internation Airport SFO) Bart will cost you $8.10 from SFO to Powell station or a cab $50.00. The hotel is right there for the cable car and electrical car. Suggestion buy the 3 days ticket $21.00/person and you can use all day in all transportation except BART. Its really worth!!! The staff was very helpfull and we had included light breakfast with juices, coffee, water and two kinds of mumfins, also from 5:00-6:30pm from Monday to Thrusday they have free beers and wine ... FREEE. 
The hotel is simple and the room was one queen bad, bath and TV...There is heater but not AC. Summer time might be hard anyway, we also did through the Powell concierge the WINERY TOUR that goes to NAPA, SANOMA AND St. Helena... we used the company Tower Tour... $75.00 they pick u up and drop u of after the tour. Our tour guide was Silvio and he tells you a bit about San Fran history and he knows everything about wine!! For our first time in NAPA it was just great!! We wanted to rent a car, however, everyone advised not to do. The traffic is very bad and if the tour you see little towns that you would not by yourself.
Have a great trip!!!