Pros
Challenging work in an exciting arena. When they say launch party at SpaceX they aren't talking yet another version of yet another GUI, they are really talking launch ... of something with almost two million pounds of thrust that comes back and lands on a boat out in the middle of the ocean. It's super-challenging and super-rewarding. Lots of folks complain about insane hours, but I don't see it. You can't mess about, but the hours and pressures aren't any worse than at any other tech company I've worked for. The technical rewards are much greater, though. I'm happy at SpaceX.
Cons
I'm not a big fan of the open seating arrangement and the parking could be improved. Sometimes managers don't really understand exactly what it is we do, but that isn't unique.