An excellent stay with brilliant staff
This was a truly excellent stay with fantastic staff and pure attention to detail. 
I travel for work at least a couple of times a month. Trips vary from one day to a week usually. I rack up about six months overall around the USA. San Francisco was a four night visit. This was a stay organized by myself and my assistant for 55 people for a four day conference and related meetings. From initial contact to final day we were extremely well looked after and the attention to detail made our lives immeasurably easier. 
I would highly recommend the Hilton based on my stay because of their exceptional staff who were constantly on hand to deal with any query. Front desk are very customer focused and empowered to help. April, the young lady at the Flite wine bar (by reception and front door) deserves special mention for her bubbly personality and helpful attitude which made many a tired conference goer revitalize after a long day. Also for conference organizers this is a brilliant hotel. John, the Food and Beverage Manager, was attentive throughout the stay and really helped our sanity levels! Lily was our main contact (her boss had just gone on maternity leave) and she was around all the time making sure things ran smoothly. Thank you all!
The rooms are very clean and well laid out to maximize use for work or vacation. My room was by elevators/lifts so slightly nosier than others I would think but the hotel did have earplugs in the room which I thought was a nice touch. There was a fraternity party the first night which required the use of the ear plugs but subsequent nights were absolutely fine with normal street and elevator noise. I like a hard pillow but have to say i didn't check with front desk if they had any...mea culpa!
There is a gym and spa that I didn't try but the spa looked very inviting. 
Internet is normally paid for (a niggle I have with all the more upmarket hotel chains plus the $3 charge for water – but best to travel with a Brita filter water bottle as far as I am concerned anyway) but I had a code which made things less annoying although I had repeat logins that were fiddly. Also nice that there was an extension cord on side of bed for all your charging needs (but you need to look under the bed!).
It is not too far from airport too and I suggest arranging Super Shuttle through internet if you do not plan to get a car. It would be $17 one way at time of writing (taxis $50 ish one way). 
Location is very good in the center of tourist sites, restaurants and China Town. There are pharmacies and shops a plenty for most of what you might need. All eminently walkable.
I would also try Credo Restaurant on Pine Street and up from there is The Occidental Cigar Lounge if that is something that takes your fancy. Both have excellent staff!
Thank you Hilton for a fantastic stay!