I would agree that you should do an away rotation in California at one of the better programs if that's where you want to be. I had similar stats to yours, and this year had 20-30% increases in applications at more than a couple places, and I was able to get interviews at all the "top programs" in my region. The only programs where I was unable to get interviews from were ones outside my region, which I thought were at least on par with the big name programs in my region. I can only crudely assume that all things being equal, your school being closer to the program or stated interest in being in that particular area is something that programs do look at when evaluating applicants for interviews.
You will probably be able to get interviews at many programs in CA without an away rotation even if you go to a podunk school in the northeast, but maybe not at a place like UCSF (FWIW- I did not get one, although I withdrew my CA apps once I realized I did want to stay in my region, but I still received a rejection letter from them anyway.)
One thing I didn't appreciate until I did an away rotation is that it can definitely work against you, as many people had said when I asked whether I should do one. You have to do some soul searching and see if you think you can make a good impression on the program you are doing it at. One month is a long time. If you come off as awkward, arrogant, inconsiderate, smelly, no one remembers you, or you say something really dumb it may kill your chances at matching there. Fortunately, I had a good experience.