We do not stay in hotels in San Francisco any more, as our son and his family live there and have a nice guest room.
But before that, we discovered the Galleria Park in the Financial District and we love both the hotel and the location.
The rooms are lovely and have nice amenities ( Nespresso coffee machine). They have a wine hour in the lobby each day at 5 ( free pours). I mentioned to the hostess that this was our second stay there, this time to meet our new grandchild, and a nice little baby gift showed up in our room the next day. The desk staff is very helpful with dining recommendations. On their suggestion we went to Belden Place a couple of blocks away. It has several nice casual restaurants; we chose a Catalan one.
We much prefer this location to the Union Square area. The Ferry Building and the Farmers' Market there are a major draw, as are the walk along the Embarcadero, and the step climbs up Telegraph Hill to Coit Tower. We saw the famous parrots on that visit. Either the Filbert or Greenwich steps will take you past homes and gardens; just try to imagine living there with all those steps!
The problem with Union Square is the seediness of the Tenderloin seems to have spread, so be especially careful of anything west of Union Square. The Powell Street BART station has an especially bad reputation as a druggie hangout ( look it up on TripAdvisor.). As in many other cities, including or own Seattle, the homeless population has exploded in the last couple of years and seems to have no solution.
I love San Francisco and go often by myself to visit the grandchildren. I happily move around the city by Muni, BART, and (mostly) walking. But I avoid walking through the area between Union Square and the Civic Center.