Wow, finally upgraded to v10, this last weekend, only to find so many of my notebooks+notes missing. After investigating, it's because v10 doesn't allow for Private/Local notebooks, one of the main reasons I use it. If Microsoft OneNote had this feature (for Mac), I'd eventually make the switch, BUT that's a huge time investment in converting 100's of notes. Sad to see this feature gone, and hope it gets added to v10.
Until then, legacy EN to the rescue.