Pros
Some branches, like Healdsburg and Sebastopol, are great to work at. Really kind and friendly people and a great environment. Pay isn't terrible for the amount of work (depending on the branch). If you work at the right branches, you'll get to work at a single service desk, too. That means you'll be able to do reference work instead of just drudging all day.
Cons
Some branches treat Specialists like dirt. The library administration is pretty terrible too, being really noncommunicative, and they've harrassed people who reported workplace violations. The union is also a total joke and desperately needs new blood. The union falls over whenever management puts the pressure on, and they've bargained for a really terrible MOU that basically needs to be burned and rewritten.