I traveled in Northern California, (San Francisco area) for about 4 years and loved it. They pay was great, loved the city and the area. I worked as regular staff in San Diego and having spoken with lots of travelers in San Diego San Francisco pays much better then San Diego. I guess you really have to decide what is your motivating factor for picking an assignment--money or the experience of getting to live in the area? If its money then San Francisco is the way to go. Personally I prefer Norcal to Socal for its beauty, outdoor activities and social aspects over Socal but thats just me.