Pros
Fun culture - everyone is very friendly and happy to chat. Good Project Management - the PMs were really adept at wrangling tasks and talent into shape. Good tracking of data and responsibilities. Independence - I rarely felt that someone was looking over my shoulder. As long as I got my work done, I was allowed a longer leash.
Cons
The hire/fire waves are brutal. I was brought on during one of these hire waves, and there was minimal infrastructure for actually getting you up to speed. It was probably 3 months before I started to contribute in a meaningful way. The layoffs are even worse. You suddenly find half of your team is gone without warning, and you're left scrambling to fill the gaps. The strain ends up slowing down production until another hiring wave comes through to temporarily relieve the pressure (until the next layoff wave hits!)