Pros
Fast paced, intellectually stimulating problem solving on a daily basis. Constant focus on improvement in all business practices. SpaceX embraces technological improvements and innovation, and rewards creative thinking and solutions. Highly intelligent and motivated workforce; authority, responsibility and accountability given to bright, young (mid to late 20s) professionals like I've never seen in previous professional work places. Designing, building, testing, flying and landing rockets - pretty hard to beat the opportunities to work on fun, challenging and innovative technology at the forefront of human knowledge and skill.
Cons
Work life balance can be challenging during major company campaigns, some projects have extremely aggressive price and schedule targets which puts high pressure on teams to perform.