Counting only new text, or also old? I mean, I think a good 25% of the book was summarizing what had happened in the previous 15 books, short stories, or graphic novels. Telling readers what they already knew if they have read the entire series. It really made especially the first half of the book a slog. I found myself skipping whole pages on the first read through as he dropped the same summaries of people we know or things that have happened before into this book that he dropped into previous books (or at least it sure felt that way). By the BAT Jim is going to have to decide if he is writing for readers of the series or not, because if he continues to write each book so it can be read by a new reader, its going to be 75% summaries of previous books and only 25% new text, and I'm not sure I can take that.
All long series go through this. I've also yet to read a long series that didn't need a book that served no other real purpose then lining up the finale and ensuring all relevant plotlines advanced, at the cost of the book of a standalone.
For Jordan, it was Crossroads. For Martin, A Feast For Crows/A Dance With Dragons. For Goodkind, I rather think it was Soul of the Fire.
For Butcher, apparently it's Peace Talks/Battle Ground.
Also, concur on the hardback. Butcher's people publish a trade paperback sized hardcover. Longer hardcovers are typically full size; his people may not have the equipment. Which I'm fine with- I want them to fit on the same bookshelf.