Personally i'll stick with W7 till death do us part. It works fine, there is/will be nothing major in W8,9,10,11 that is so earth shattering it'll be giving me so much additional value it'll make up for being trapped into MS's version of Apple. Security is not an argument, you can't make an OS safe against human stupidity. If you get an email with "your bank needs you to confirm your details" and you answer it no OS is going to safe your ass.
Already compared between 7 and 8, 8 is a bit faster if you have a stopwatch at hand, it has a few extra features which are bad copies of existing 3rd party software and an extremely annoying interface which hurts my eyes.
So what it comes down to the general consensus is when you change w8 back to w7 it's pretty good.
Wow, that's some selling point.
Windows is at a dead end because the codebase is way beyond anyone's grasp to be able to make any changes without introducing a gazillion of bugs. When it's done it's done.
So they just strip off the layers, go back to the most basic core and start anew. Unfortunately with this idiotic concept of having the same interface for completely different usages. As it seems there are enough suckers around to buy into it, but then again there's one born every minute.
Once, far way in the future, hardware will so far advanced it'll be really possible to have HAL around to do your wishes, till then it'll be just down to what we've got now. A screen, a keyboard and sore eyes.
No need to add a sore back into the mix from making superfluous repetitious motions to touch a screen. Nobody stays 18, this stuff has to work also after you have been using it for years on end without saddling you up with bad eyesight and RSI in just about every upper joint of your body.