Another vote for USC for many of the reasons mentioned above re: student quality of life, alumni network, weather, etc.
USC’s Thematic Option program looks amazing, and it will give you access to top faculty and a cohort of very intellectually engaged students. Would you be living in the new USC Village?
You can’t go wrong with either school and if the net price puts them in range of one another, you should go with your gut, If you end up choosing Cal, bear in mind that housing is not guaranteed after the first year (and that forced triples for freshmen are not uncommon). Moreover, certain majors are impacted and it can sometimes be difficult to graduate in four years because you can’t get all of the classes you need.