Pros
At UC Merced you end up being a big fish in a small pond rather than being a small fish in a big pond like most universities. As a researcher that means lots of equipment and attention. Also, more finding to go around. In Cognitive and Information Sciences, we usually got our number one pick of teaching assistant positions. Instructors of record were always conscious of your research demands and made the teaching responsibilities pretty basic.
Cons
Sometimes there is a shortage of teaching assistants, which is usually unheard of at other universities. And because of this shortage it is possible for teaching assistants to be overworked. The teaching assistants along with tutors and readers are protected by a union contract but enforcement of the contract can be tedious.