> I can't see which book is worn from being read and re-read, or brimming with notes and scribbles.

It's amusing to read that, for on one side of my family, scribbling in a book would be considered a most heinous crime! I keep any writing to the flyleaf if the book is a gift, but don't otherwise write in them. Another thing that complicates the matter in my family is that we have always been serial second-hand book buyers, and in such a case a book's physical condition is not necessarily an indication of how much it was loved by its immediate previous owner. On the other hand, my grandmother tended to insert relevant newspaper cuttings into the book for the benefit of future readers!