Pros
The work is amazing. The mission amazing. The contracts amazing. There are thing you do there that you will never be able to explain to anyone but will fill your heart with joy and give you a sense of confidence and purpose like nothing else. For the duration of your time inside spacex you will smile and live in awe of the place and the people.
Cons
You will trauma bond with your co-workers. You will see them develop drinking problems, stress related health issues, psychological trauma. You will eventually break under the load. You can do EVERYTHING right and because someone else broke the weight will shift to you and destroy you. You will be redlined for years working for them. And by the end you won't even realize what a ghost of a human being you have become. Budget a year of recovery time doing nothing difficult after you leave, at least. I don't regret taking the role. I just wish I knew when to pull the cord and get out.