No problems
We stayed at the Argonaut as we picked probably the busiest weekend in SF and there was nothing else available. We therefore paid over the odds and so this probably colored my view that I was a little disappointed. The room was very small with a view of a brick wall and there was no 'hotel buffet breakfast' which I enjoy so much. There is an attached restaurant where we had breakfast one day but I would recommend you go further afield - there is a great bakery at the wharf a little way down the road which does casual downstairs and table service upstairs. 
The hotel was all fine with no problems but other than the doorman, not that helpful. There were a couple of nice touches for the children but not worth the money but as I said, we paid around $500 per night. 
The wharf area is a bit too overrun for my taste so would stay a closer to union square if I went again. The argonaut is well placed for Alcatraz with only a 15 min walk to the ferry.