Pros
The company has a good set of values and the leadership actively works to keep the company aligned with those values. There is a lot of trust given to employees. The honor system is used liberally The vacation policy is to take time off when you want to (with a reasonable amount of forewarning.) It's a fun environment. Employees can regularly be found in the break room playing ping-pong, foosball, video games. There are numerous groups of employees that regularly get together for rock climbing, hiking, biking, studying, etc.and these groups are easy to find and always open to more people.
Cons
While there is a place for them, It can be a difficult environment for introverts. The company rewards initiative and marketing oneself well by showing off good work, and this is not easy for all personality types. Benefits (Insurance, 401K matching) are not exceptional.