1: the Pages column can't be resized (unlike in Quark 7) to display the full range of page numbers in each chapter -- so what could be a useful navigation tool for long Books is useless. VERY annoying.
2: the Book palette, on opening, always defaults to a size that's way too small to display its contents -- every time you open a Book, you need to resize the palette (then try to resize the columns -- haha). The Book palette should remember its last size and position.
Having just finished work on a 550-page Book with 18 Chapters, these problems are high on my Quark annoyance list. I've requested fixes (which should not be difficult) in the past, but have had no response.