Pros
The work! There are only a handful of companies on the planet making the kind of impact that SpaceX is making. Not only are we shaking up the aging Aerospace industry and pushing through technological boundaries, but we are also working on projects with the potential to change human history. You definitely get the sense you are part of something big here. You also get the opportunity to work with some of the smartest people on the planet, and you get to witness some incredible feats of engineering. The campus in Hawthorne is expanding, and there are a lot of nice little benefits like an on site health and dental clinic, company store with cool gear, and many locations to grab cheap food.
Cons
Ok, the work hours are long, but the days go by quickly because you're genuinely interested in the work you're doing. I was also surprised that the pay is lower than the typical tech/aerospace company and they don't offer a 401k match.