I'm interested in all the responses as I've only stayed at one park in San Diego and that is MISSION BAY RV Park. I've stayed there three times over the last few years and find it very convenient for biking and walking along the water.
The spots are a little tight but when I visited (generally in Feb. of each year), the park was not full and very comfortable. I always heard 'Campland on the Bay' was full of children so I was not partial to that. I wanted to be close to the water and Mission Bay RV park filled that desire.
It's certainly not fancy but has security and is fenced. Also, I never noticed any traffic noise in the times that I stayed.
Safe travels,
MM.