My desktop has had no problems worth mentioning with Win10. After the latest big patches a week ago, my laptop's power saving features got royally screwed, but after a bit of registry tweaking and fighting the settings a number of times, it seems to work again.

For anybody playing modern games Win10 is a must due to the DX12. I haven't particularly missed Win7. Never had the abominations called Win8/8.1 on my PCs, fortunately. It took a bit of getting used to how this version is much simpler graphically than the past ones despite PCs being stronger, but it's not a deal breaker. If I had to mention a single thing that bothered me from the beginning and still does, it's MS dropping the old photo viewer. The new one is a pos. But I haven't got around to messing with the registry to enable the old one, which apparently still is there, but too well hidden unless you have an upgraded Win10, not a fresh install like I do.