Pros
SpaceX will fundamentally change the arc of the human experience in many different ways. Everyone knows about reinventing space access, plans to colonize mars, reinventing satellite telecommunications, etc. But what few people appreciate is the practical clear eyed view about long term technology development, business value creation and social good that will result from these activities. Many companies talk a good short term game and can entice you with lots of fluffy bait. But few companies can combine the elements above around a meaningful long term mission and purpose. Makes getting out of bed and coming into work pretty easy every day.
Cons
I would not recommend this company if you want to be a dilettante. Wasting time, energy and resources on distractions is a big no-no. This company has a few clear cut primary missions and everyone has to bring laser sharp focus on delivering against these missions. If you don't have the ability to focus, continuously raise your game and execute against the primary missions, you probably might want to look elsewhere.