Pros
Good life/work balance. Can take time off when needed. Great health/retirement/commuter benefits. Good support for working from home / remote work. Although slightly lower than general tech, the pay is above average for working in libraries. More up-to-date on general technology trends than most academic libraries. A friendly atmosphere where people are allowed to speak their mind.
Cons
Sometimes a very confusing environment to be in. Often not sure what the overall goals and direction are. A little bit too "chummy". Habit of allowing managers to hire their friends/former coworkers/romantic partners/etc. Not a place to expect promotions. Structure is very flat and most new positions are almost always filled by people poached from other institutions/departments. To move up, people usually have to go to another institution/department, then come back after a few years. This is very common problem in academic settings, not just Stanford. Just like in real life, you can speak your mind, but it usually doesn't change much.