Unfortunately........I knew all these answers earlier this year, but after I bought my Sidi's, (verbrata II air) I forgot most of what your looking for.
But I do remember this, the Verbrata and Ver. II are a hinging system that is patented by Sidi. It's their system of protecting your ankles along with allowing ankle movement. Verb. air...is obvious...it's vented. Verb. race........is different, and more expensive, because of all of the removable hinging parts that are replaceable. The thought is that when your racing and you crash, your able to replace parts easily and bring your boot back to a completely safe product again.
Wish I remembered more, but at least I have some info, rather than just an opinion of how I would spend my money.
They are a great boot
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Fully Shredding
Scraping pegs, and using "all" the tread
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