a lot more support and guidance. the classes you take supplement the MCAT studying you do with your cohort, and the specialized classes are taught by medical school faculty. other postbac programs advise you to take random upperdiv science classes and electives. ucsd's program is designed by the medical school, so they pick classes that medical schools will want to see on your transcript. you won't be wasting your time. not to say that the other programs are bad, to be honest i'm not sure about the northern cali ones. the faculty to student ratio at ucsd's program is great.