I have been there, but only once, perfect fall conditions, minimal wind, <2' tide change, an excellent selection for a first over nighter with a new boat. Every ferry leaves a wake, and they go by close on the way to/from Larkspur, every commercial boat from Chevron Longwharf north sends you a wake, some of them result in what we call "table clearing moments", which could include alcohol abuse, spilled wine.
Last Friday I was just sailing through that zone from 5-7 pm. I think we were rocked by three, maybe four ferryboats during the commute hours, and one ship coming down from the delta, even in motion, under sail, that zone was not peaceful. When I anchor there again, and I will, I have rocker-stoppers to deploy.
I do prefer China Camp, though a friend tells me Belvedere Cove has its good points. There is also a bit of a hole off the Marin Islands that I want to sample sometime, I've cruised past it many times since I keep my boat near downtown San Rafael.
Just north of Rat Rock off China Camp is another hole, also 7', I've done that twice w/o much rocking and rolling from the passing ships, can't really say why. It is above where most people hang out south of the pier at China Camp or off McNears, but still easy to row to for land access if needed.
