I've been to Miami a bunch but never during Art Basel. I kind of had the impression that it was one big party and the art was just an afterthought. If you plan poorly then that's probably what you experience would be, however there is so much great art and music from all over the world that everywhere you turn there is something interesting to experience.
I really enjoyed it and I particularly enjoyed meeting people from all over the world and exchanging perspectives.
It's worth checking out, see you there next year?