We stayed at the Chelsea and were quite pleased with what we found. The rooms were large, comfortable, clean, and nicely decorated. In a city where parking can cost you an arm and a leg, the Chelsea offers free parking in their own street level and basement parking areas for all guests. Bus service (Muni) to Fisherman's Wharf and Union Square is only a block away, which is also nice. The staff was very helpful throughout our stay: making recommendations, giving directions, and even handling some faxes for me. We liked the security of the Chelsea too. The only way to get to the inside corridor rooms is to have a room key, which also accesses the elevator lobbies at street level and in the basement garage. I booked my room on the net here and got a great Internet rate of $79 a night for a king bed room.
As much as I like the Chelsea, there is one drawback to its location. Lombard starts to get noisy with traffic around 6:30-7am. If you want to sleep in, or you're a light sleeper, ask for a room that isn't on the Lombard or Fillmore side of the motel. The inside rooms don't have much of a view, but they are somewhat quieter.