Pros
Flexibility in so many forms- when you work, where you work, what you work on. It does very much feel like my career is in my hands, and that the company is genuinely just interested in matching whatever I am able to contribute with the larger goals. And it's amazing having every person you work with be one of the best in the world at what they do.
Cons
All of the pros are double edged swords. They come with the crushing weight of knowing that nothing is ever enough and everything is on you. There is seriously no such thing as giving 110% here. If you can handle more than you're currently doing, then you have failed at pushing yourself and proactively taking on more responsibilities. Most of the people around you (that have survived) have already been pushing themselves to constantly grow like this for many years and you'll likely never catch up. It requires knowing yourself very well to be able to accurately see where you fit, to set your own boundaries so that you bend without breaking, and then to clearly communicate those boundaries so that noone is expecting more. If you can't do that here you're guaranteed to become stressed out beyond imagination, to disappointment your peers, and be unable to prove your worth.