Love the new sorting features as well
I'm on the fence about the category thing...since I was kind of attached the the categories I'd given the books in the first place...and as someone who has alot of books...this change added a significant number of categories (and essentially removes my ability to sort the books by type).
But until iBooks adds a better way to deal with this, I guess we're gonna lose somewhere.
Just wanted to add my thanks
If you ever need another OS X tester let me know!