There are some pretty good challenges to one's perspective in there, but it gets monotonous after the second book. It was a chore to finish the third book; I don't know if I'll ever get around to reading the fourth book.
The fourth is actually the best, in my opinion. One of the most impactful statements I've ever read about being a scientist is delivered by Wonko the Sane.
I had no use for the foray into soft pornography mid-way through, but otherwise it was well worth the read.
