I think I'm with MrTBC on this one...I don't think I totally understand the film...
Because while I did really enjoy it, I don't understand why everyone is calling it brilliant.
VAGUE SPOILER ALERT
I tried to follow some threads that made me think it was doing a mixed, layered sort of thing with the film's Jack story and the novel's story of Jake (à la Adaptation).
But that idea didn't follow through to the end. Or maybe it did and I just missed it?
If I'm supposed to take it all on face value then I kind of dislike Owen's character and that takes some of the fun out of it.