Pros
Benefits are terrific, especially the monthly-day-off. Good fit for system software folks. Everyone seems to work well with each other. No obvious politics, but then it is a small company so you wouldn't expect that much anyway. Great place for people in East Bay: very technical work, both challenging and rewarding, and short commute! Yay! Processes are pretty lightweight (agile-like, kanban) so you are mostly doing real work instead of having meetings. Upper management is pretty transparent about what's going on, which is refreshing.
Cons
My personal experience has been great. I have heard that some folks can have a strong opinion about things and might take it too far, but that shows they are passionate about their work, so I see it as a good thing. Again, it's a small company so some people might be a bit squeamish when it comes to confrontations.