Pros
You are surrounded by driven, intelligent people all with the same goals. The facilities are great - free coffee/frozen yogurt, the meals are good and cheap. SpaceX also offers different speaker series, both with executives within the company and outside of it. In my experience, senior management has always been accessible and willing to hear your ideas/help you out. It's also very inspiring to be led by Gwynne (President) and hear her speak. Also, you are working on rockets and spacecraft that actually go into space. That's a pretty big pro.
Cons
Like a majority of aerospace companies/startups/tech companies, the overall employee makeup is mostly (white) men, which can be daunting at times. However, there are more women/minorities here than you would think.