I buy lots of silver-age CGC books and was just using this one as an example as I just received it. I really don't see much of a difference from the books I have purchased whether they are in new cases and recently graded, or new cases graded a few years ago, or even against the 1st and 2nd generation holders. Most books are graded spot on to me, a few may be under-graded and a few over-graded but always within a half a point either way.
Also, several of the books in the pictures above are not from CGC.