Positiv:: Great location, good price, comfortable, professional, courteous staff.
We had a room on the top floor, which was clean and quiet, with a ceiling fan rather than AC. Despite typically being a light sleeper, and expecting issues with street noise, I slept better there than I have anywhere in years, not really sure why (could have been the 12+ miles walking each day in wonderful San Francisco).
The hotel is in Union Square, with its incredible shopping and conference centers. Chinatown is about .5 miles away (and a very steep hill), and Fisherman's Wharf about 1.5 miles; a fun walk if you're up for it (but Uber is fast an inexpensive, especially the pool option).
If you're looking for a plush, modern American experience, this isn't it. If you're looking for an affordable, comfortable, centralized location to explore SF, or attend a business conference, this is a great choice.
Negativ:: Rooms are small, no air-conditioning (though not really needed) and there was no real work surface for a notebook. Not a place to get work done. Bathroom was dated, but functional.
There's no fitness center in the hotel but you get free use of a health club around the corner with lots of good gear and yoga classes, which were great. There's no coffee in the room, but there's a 24 hour a day brew available in the lobby with cookies I found impossible to resist. Wi-fi is free and fast.