Subfixer, living in San Diego, I've occasionally seen 3 of them tied up at North Island. Four in the same view would be an impressive sight indeed.
Butchy, about fifteen, maybe twenty years back, I got an informal tour of USS Drum (I think, definitely Permit class if not Drum) from her XO. The XO was giving a little tour for some of his friends, and I was able to get on through the nebulous connection of his wife being a good friend of the mother of a good friend of mine. I think that it was the most interesting dockside tour I have ever taken. As an engineer, I found it it fascinating how they are able to cram so much stuff into such a little hull, yet still have everything all accessible, and at the same time making the boat as roomy as it is. Amazing boats.