Windows 8.0 and 8.1 i hate stock,I have to make it more like Windows 7 completely turning off Metro or whatever they now call it now, and disabling the stupid and pointless swipe screen before the login screen & removing everything else that's "App" style that il never use that's using disk space.
But now that i have,It feels exactly like Windows 7 but better,Faster.
If your running Windows 7 currently,personally I wouldn't say its really worth upgrading yet,Wait for Windows 10.