Pros
Very open and accepting place to work. There are good camaraderie, good hours of work, and lots of room for growth and learning. The management team tends to be very understanding of employee issues (almost to a fault) and receptive to feedback. The health benefits are totally free and really great. Beer fridge for those over 21. Very cool office. Sweet quarterly parties. Helpful (if sometimes delayed) quarterly 1-on-1 reviews. Quickly-growing startup that's done a pretty good job of not over-extending itself.
Cons
Some people with negative attitudes (see those 1-star reviews) are/were allowed to stay on the team for too long due to the understanding nature of the management team and some lack of a clear system of accountability for behavioral issues. That can actually be more of a morale killer than anything else. No employee-sponsored retirement plan (yet). Lacking some structure/policies that could be helpful.