Pros
From the moment I first stepped into the SpaceX factory, I knew this is where I wanted to hang my hat. I was immediately drawn to SpaceX's blend of a far-sighted, humanistic mission and short-term efficient business acumen; SpaceX is the company to join if you have big dreams of helping improve the course of human history, but also want to see these dreams practically realized instead of left on paper. Compensation and benefits provide a comfortable life, but much more so than that, I am energized to come to work each day in our incredible rocket factory and feel proud to work with such smart, motivated colleagues. 3+ years into this job, I don't think there are many other places that I would feel the same way; I am in it here for the long haul all the way to Mars!
Cons
The fast-paced work is not for everyone: you have to be willing to find your own work-life integration at SpaceX, and be your own advocate in this regard. I have found that management is willing to listen when you do speak up. I work ~50 hour weeks and take regular vacations; I have no complaints.