Honestly, this book is essential if you have 4 Against Darkness. The setting and premise of the Flower Demesne is highly original and wonderfully evocative. You even have to forgoe a certain amount of combat and instead find yourself involved in weird courtship encounters!
The new classes are great too but the real winner (apart from the setting) here is the section on potions. Its incredible!
This book could completely change the way you play 4AD. Hunting for ingredients for potions is now a fascinating and lucrative objective that will see you seeking throughout many of the other books in the line already published.
I highly rate this supplement. Buy it immediately!!