I did the San Diego Granfondo both last year and this year and I must say the organization was terrible. I won't do it again.
I heard stories of them running out of water at various rest stops both years. Last year it was warm (80 F) and from what I heard they ran out of water at the top of the long climb. This year they ran out of water after the rest stop after the climb.
This year they didn't provide a route sheet.
This year they started closing some of the rest stops early and when I got to the finish they had closed the event expo. The meal at the finish was also cold and sparce. They didn't even provide all the swag promised as some of it didn't get through customs on time. Still have yet to receive it over a month after the event.
They also chose terrible roads. While they are roads I regularly train on, the last section is attrocious (ok, tought to say that with Paris-Roubaix coming up, but for tarmac it was bad), lots of pot holes, road chewed up, and railway crossings at approximately 30-45 degrees. If this was in Milan some older rider would organize a protest.
I heard there were numberous crashed on this section. Not a sectioin I would send a large group of riders.
Just to show it's not me, here are some reviews: http://www.active.com/triathlon/san-diego-ca/gran-fondo-colnago-san-diego-2010#Reviews