#1. They use a split shank hook, so an o-ring is not needed.
#2. I get quite a bit of missed walleye with the #8. Especially on the Size 3 Shiver which also uses a #8 hook. I upsize all of my hooks on Jigging Raps and sometimes even add a Fastach clip to get the hook further from the body of the lure to increase hook up percentage. When you upsize a large Ice Darter, Puppet Minnow or #7-#9 Jigging Rap to a big Daiichi #6 treble, there's no hang up around the line. Not sure about a Shiver though. Most guys ice fishing the Great Lakes upsize their hooks. I probably wouldn't if I was fishing inland lakes in MI, since the fish are usually smaller; I'd just use the Fastach.
Just trying to figure out if I should order the split shank hooks or not.