Yeah i took 12 units at UCB ext and you take courses with people in the UCSF post-bacc program. Im currently debating going back to UCB ext or going to sfsu's post-bacc. One thing i didn't like about UCB extension is that the courses are detailed but many students complained because the prof wouldn't say how detailed the tests would be. I studied my ass off and did well on every exam except that i didn't take the teachers word when they said the test wouldn't be too detailed because that could mean different things to different people. The SFSU post-bacc, ive heard, is more structured and there is a sense of camaraderie. In UCB ext i sometimes felt the yale, stanford, and UC kids were trying to leach any info they could from you but wouldn't help you in return.