Pros
SpaceX was a extremely fast-paced and rewarding experience. From day one, I was given the tools to learn almost anything about the company or the products I needed to for my projects. The launches are really cool to watch with other employees, especially knowing that you physically touched and worked on parts of that launch system. There is a very competitive and informative company culture that means most of the time everyone is very focused and attentive. I personally really liked the work hours, and I would be fine working more, but they cap interns at a certain amount per week. Partially because of this, most interns hang out together outside of work hours, and we had a lot of fun over the term.
Cons
Because of the group I was working with and the particular timing of my internship, I didn't get the chance to interact with my teammates as much as I would have liked to, and I ended up working on a slew of projects all over the site. Additionally, among interns there is somewhat an atmosphere of competition in terms of intensity, but it is not as bad as I was expecting. Unfortunately, it is very hard to get hired at SpaceX, and few interns get hired on full time.