Former UC SMP student (now M3 at Ohio State) here:
1) The same-year app support. I was getting long in the tooth and felt that only 2 programs-- UC and EVMS-- really seemed to have a track record of getting students in the same year. Also, I wanted to go to my home state for medical school. Now, clearly that didn't happen, but I do credit the UCSMP with getting me an interview back home (on the west coast), and the subsequent rejection I got is probably more on me than any reflection on the program.
2) As I said, the same-year support is why I chose this program. That is probably the best feature (that and opening you up to all those juicy Ohio schools with low in-state tuition) of UC. I got my first acceptance in January, and it was an enormous load off my shoulders for the rest of the year. I can't imagine the unrelenting stress of a two year program.
So, here's the deal: Getting into schools on the west coast is hard, it's the most difficult geographic area to apply to in the country, and it's not even close. The fact is that students that need an SMP to get into medical school are typically not the kind of students that get into schools on the west coast. Not even looking at their website I am sure georgetown has occasionally sent one out there (just because of sheer numbers of students) but it's the exception not the rule, and often those students are the sort that don't really need an SMP after all. If I were you, wherever you end up going for your SMP I would absolutely apply out west and make that my ideal result, but I'd get comfortable with the idea of it not working out, and make my number one goal just getting into medical school already.
Beggars can't be choosers, and such.