Decent hotel and great staff, but not the quietest room.
I stayed at this Hyatt Regency for a conference, which was also located in the hotel. If I could give the hotel 3.5 I would have, but some spotty service with packages for the convention knock it down to 3. 
To speak to the conference/banquets side of things-- it took a really long time and a lot of prompting to get all of the packages that had been sent to me. For most visitors this will never come up anyway, but it was certainly annoying. Just something to be aware of if you are here for work. 
To the hotel itself and rooms, the review is more positive. Every staff member I came in contact with was very friendly and helpful. even more than would be expected. I found the room itself to be fine-- seemed clean, furniture was fine, bed was above average, and contrary to some other reviews, my bathroom was plenty spacious with a large countertop for toiletries. Nice big desk for working, plus a chair and ottoman by the window for reading or taking in the view. The TV swivels so you can watch it from wherever you like in the room-- I'm surprised by how many hotels don't have that little detail. 
The con to the room was noise. I was on a low floor-- the the front desk person did offer a higher room, just with 2 beds instead of 1 king-- but I could hear noise from the outside all day and night, as well as music from the atrium. It wasn't terribly loud, but if you are a light sleeper, it will definitely be noticeable. I ended up downloading a white noise app on my phone and was fine with that on. 
Location was very good, close the the piers an the market and public transportation. I was able to take the Bart to the airport for $8 and it took about an hour door to door-- not bad at all. Overall, I would recommend this hotel, but ask for a high floor if outside noise bothers you.