As a writer I will always make note of how authors do things. I will make note of a passage and go “this is how the author makes passive voice work,” or “note the adverb use here, contrary to oft-stated opinion.” I’ll write down any phrase I want to remember in the future in a separate word document. That being said I DON’T write anything in the actual books. I’m very OCD about my books, I’ll buy used ones but I WON’T touch any with pen-marks or dog-eared pages. And ANYBODY who touches one of my books with ink will be horribly butchered in as gruesome a manner as I can think up.
I think if you want to find out what others thought of the book, you have the internet for that.
Also brand new books are NOT all the same. Hard-back books fall apart so easily these days, and mass paperback have shitty spines, books localised for America are different to those localised for England and have you ever got your hands on an ARC copy of a book?