I managed to get Windows 10 installed in virt-manager however suffer from some display lag. It's very minimal but noticivle when running my magnifier. Another issue I suffer from is that there are two small black borders on the left and right when running Windows. My resolution is 1366x768 but it defaults to 1280x768. I use QXL alongside spice for my display.
It's using very basic software video acceleration. This is why you need a second GPU for decent video acceleration with QEMU/KVM.
Not to mention I'm using HD4000 graphics. Seemed to good to he true I guess...