My only, er, "serious", I suppose, use of Win10 is on a keyboard PC that came with it and flat out refuses to install an alternative OS, the start menu annoys the hell out of me, the anniversary broke the OS and had to revert itself, everything looks flat and dull like someone just used Paint to draw something that looked like windows 7 without the three-dimensional style that had been a mainstay since Win3.0, and of course, the spying aspect, not a fan of 10...
And yes, I know there's aftermarket ways to fix all those issues, but, why the hell should I? You don't buy a brand new car that you have to repair the engine and bodywork before you can drive it, it should work right out of the box without having to have things installed, uninstalled, blocked and skinned, I can certainly understand why Which? condemned it, it's blummin' awful...