Stephenson is a...polarizing writer. He tends to break what are thought of as the rules of writing (show, don't tell; don't use massive, chapter-long infodumps; focus on character; etc.) and produces literature that is a story wrapped around ideas, rather than ideas that tell a story.
Of course, I think he does it extremely well and I don't read his books for deep character insights, but for the usually absurdly detailed and complex philosophical problems wrapped in several explosions that make up the storyline. It's a matter of expectations.
Anyway, I loved Anathem. I thought the premise was brilliant and I found Erasmas to be a surprisingly compelling character (by Stephenson's standards, of course). But the weirdness of the story and how he weaves in surprisingly complicated Platonic ideals with Derridean take-downs and...
Anyway, if you liked Snow Crash, read Cryptonomicon and if you liked Cryptonomicon, read Anathem. It is well worth your time.