Win8 wasn't properly finished. Vista failed but it was a massive change from Xp and they couldn't, I believe, tailor it properly. Win8 was a reactionary attempt at following multidevice OS / smartphone UX trend with the new found creativity of Metro, but really it felt like a demo, things were too big, too frail, too crude. Win10 doesn't convey that for me, they took the nice elements of Metro design language, adjusted and integrated them into a flat win7 UX.