Pros
SpaceX is trying to change the world for the good of humanity, and being part of that is an awesome experience. Plus, the company is a great place to work. The people that work here are smart, passionate about what they do, and not afraid of hard work. Employees are given the opportunity to take on big challenges, which is incredibly rewarding. And come on, you literally get to work at a ROCKET FACTORY. How cool is that?
Cons
Despite how much the company has grown it still seems like there's always too much work and not enough people. As pretty much every review says, you'll likely work a lot of hours, so you really have to make an effort to maintain work/life balance. Many potential "cons" depend on your personality and the type of work environment you prefer. For example, schedules and goals are agressive and employees are given a lot of responsibility and are expected to consistently perform at extremely high levels. This can either be really rewarding or super stressful depending on the person. (But to be fair, even people who like this type of environment can burn out after too much of it.)