I am going to start off and say - this is not the Hilton - but it never advertises itself as such, and a Shared Bathroom "European Style" (I'm European and never seen this in my life) is very common in San Francisco on budget hotels - so make sure you read your booking.
That being said, my review is as follows:
Hotel Staff - I've stayed here a couple times now and the couple that work the front desk have always been incredibly polite and have never had any issues. If you're looking for somewhere cheap and close to central - these guys have you covered.
The Room & Amenities - Since my last visit, things have got a bit better, it feel like the rooms are cleaner, and there are more amenities on the included sink (soap / lotion / body wash etc) and more towels. The Room is cheap and cheerful, has a couple of draws, a chair, TV and a decent sized bed. There are a couple things it could do with - some wall hooks for jackets / towels after shower etc, and maybe some brighter bulbs for the main light in the room - it takes a long time for the warm bulb to actually start giving off light. The bathrooms whilst shared have always been incredibly clean whilst I've stayed here (3 times) and never had any issues with waiting etc. Only other side note - for the TV's move the TV box behind the TV - don't have it just hanging out. I honestly feel with some fresh paint / new curtains and those little tweaks, this place could easily go from a 2 start hotel to 3 star vibes.
Location - It's near a highway, but when you get later in the evening you don't hear it. There is a dive bar underneath and a club behind but honestly aside from one time there was a metal band performing, they've never kept me up or awake. In the morning you get a nice light through the window as well which is great for waking up naturally.
The Building - This is classic San Francisco "Stick Style" architecture which just oozes character - this building has the history too if you look it, famous people used to come party here!
Finally, for Solo Travelers, this is a nice step up from a Dorm Accommodation and for Solo Business that just want a cheap place - it's not bad at all.
In my opinion it's one of the only fair priced hotels in the city.