To me, I like to have a high grade, but I can live with a 9.4 or a 9.6, especially if I am buying them on ebay.
There are some really good sellers that put a lot of books through SS process so odds are they are going to get some really high grades, but end up with some 9.4-9.6 grades also. Just law of averages with submitting books.
Bottom line, and I think the others in this thread would agree. If the book looks nice to you and you would love to have it signed, that is all that really matter! Join the club James! We are getting jackets...