Anathem was kind of a slog for the first 200-250 pages, but then it started to get good, and then awesome, by the end of the book my mind was thoroughly blown.
My wife read my copy after me. If I remember correctly, she more or less read up to that scene in 5-10 page increments, and then read from that scene to the end in most of one night.
That was, bar none, the best reading experience in my life.
With respect to Anathem in particular a lot of the problem is you didn't really understand what was going on for quite a while and I found that made it a bit of an effort to keep going.
Damn, I need to read that one again. It's been too long.
I kid, I kid. I ended up loving Anathem too, although I seriously struggled to get going.
I remember around the 200-page point thinking, "ok, now we're getting started."