The Xanth stuff has gone downhill because of the dang puns. A bunch of fanatic fans and trolls send Piers Anthony hundreds of thousands of puns between books and he always devotes at least 1-3 chapters to jamming in as many fan puns as possible.
Used to, you could just SKIP those chapters, but the latest ones in the 20s really became all about the puns, strung together with "excuse plots" that just got more and more out there. "Fawn and Games", IIRC, was about planet hoping through, like, 4 different miniature planets that kept circling around one princess' head. It was completely dull and forgettable, imho.
