When a lot of the dialogue is concerning theoretical physics and the science of relativity in regards to space travel and its effect on time, you're gonna lose a few people.
I liked it. There's a lot of subtle and not-so subtle homage to Kubrick. The 3rd act is a stretch, with the usual Nolan plot holes, but all in all it's very enjoyable. Definitely not a film for the Transformers crowd though.