It depends on how the people handle them at the shop. I'd say over 90% of the books out of the Diamond boxes are 9.6-9.8 most of the time. But I know there are people working at the shops that don't care about the comics like some of us do. I used to pull comics and put them in the "folders" (really, paper bags) for the people who subscribed at my LCS and I treated the comics like royalty. The manager of the shop? Grab, and stuff. It was painful to see sometimes, when a subsciber had a large list and hadn't been in 2-3 weeks, the manager would stuff 2-3 more comics in an overfilled bag rather than get a second bag. I'd always go behind him later and get a 2nd bag, and relieve the poor comics of the stress of being packed too tightly.
I also pulled my own books, too. I can guarantee that the later part of my OO collection of mutant books are 9.6-9.8 at the least.
Last I saw, this shop used to put books out flat, on a table, for people to get their copy from. No bags or boards, you can buy those at the register for 25¢ extra. I never liked that. Shops close by, newer shops, all B&B the new comics on the rack, and I admit, I like that better for two reasons: 1) people can't shuffle through the comics on the rack and mess 'em up and 2) sometimes the employee behind the register doesn't care about the comics as much as you do.
-slym
(thumbs u