UC has a higher payed instructors, meaning they are more devoted to their work and their students.
UC are famous nationwide and very competitive to get admitted (not all).
UC graduates have a higher percentage of getting into their career compared to the Cal State graduates.
UC sports team are in the national division while Cal States are in the state (lower) division.
You can write a long list of the difference between a Cal Poly student and a UCLA student. And I do mean a long
list. I don't know about UCR
though.