Pros
Working here means you are running at a hundred miles an hour. You take ownership of your responsibilities and you can make a difference to the bottom-line. Everyday is a good day when you have meaningful work, and you are surrounded by colleagues who know what they're doing. Within reason, there is excellent flexibility - you don't have to stress over whether if your leave will be approved or if you will be marked for having to care for a sick toddler. When you submit your request for leave, take a blink and its approved.
Cons
It can be overwhelming, and you can get exhausted. Then you take a break and come back energised. And if you are not delivering as expected, you will naturally feel the pressure to either shape up or ship out. Hierarchy being so flat means limited chances for promotion.