For me, upgrading my OS is like going to downtown just to buy a new hammer with a clock included.
The old hammer works fine, and why the fuck I would want a clock-hammer? I guess it may be of some use of some people, and I may use the clock feature once in a while but I'd be more than happy to just use my old hammer.
Still, Microsfot, the hammer maker, basically says after some time your old hammer may turn into a angry wasp if you don't upgrade because they stopped giving it anti-wasp updates, so you decide it's better to upgrage, not because you want the new features, but you are afraid of being stung in the ass.
Oh, and the upgrade went without any flaws outside taking ages to start. I see no clear advantages over my old Windows 7 and honestly, I prefer the UI I'm used to but just the fact I could seamless upgrade without re-installing and formatting is a big plus.