This being the fourth book in Fforde's Thursday Next series, it's probably easiest to simply compare it to what came before.

I felt like Fforde was starting to run a little dry of good, funny ideas and so resorted to some ridiculous, more-silly-than-funny ideas in this one. Maybe a little less desire to make something really hilarious would have served the book well.

Anyway, for those who've enjoyed the first three books (which I did), there's no reason not to read this one as well. It wraps up the series nicely and it's not terrible or anything, just a little strained compared to the earlier books (particularly the first two).