Fforde's books are always very readable, and enjoyable, but when you've seen an author's best work, you want the next book to improve one what's come before. This is the second 'Last Dragonslayer' book, Fforde's series aimed at kids/teens, following the further adventures of Jennifer Strange. However, she's no longer the Last Dragonslayer (and dragons don't feature at all), so perhaps naming the series after the first book in it was a bad move.
All of Fforde's books so far - the Thursday Next set, the Nursery Crimes, Shades of Grey[1], and
Last Dragonslayer - involve Earths unlike our own, with societies, norms, and creatures that seem unusual, curious, fantastical and funny to us, the readers, but are accepted as every day and familiar to the characters living in these worlds. The stories usually involve a large array of different plot threads which are all relevant to the main character and somehow tie together to make for an exciting and satisfactory climax.
The Last Dragonslayer series (including Song of the Quarkbeast) are aimed at a child/teen market, and this just means that there's fewer of these tangential plot threads, and the logic required to tie them together is clearer, and many explanations are given to the reader in the narration (whereas in the adult books, sometimes you have to work it out for yourself).
On the whole, I did enjoy the book, but it didn't quite live up to my memory of Last Dragonslayer, and is not nearly as satisfying as the early Thursday Next books, the Nursery Crimes, or Shades of Grey (which I consider to be Fforde's best work so far).
[1] Please note there is no number in front of this title. Fforde's Shades of Grey is a BRILLIANT book and is about a curious future where class is based on the colours you can see. I eagerly await the sequel, and wish he would get around to writing it instead of more Thursday Next, which has seriously gone down hill since book 4.