I am running QEMU-KVM. My Windows XP virtual machine and other machines run really smooth and quick with the same type of settings (actually less much RAM and CPU allocated), adjusting for 32bit XP and 64bit Windows 10.
I don't think most of my performance issues with Windows 10 can be solved by moving to VMWare, or even running it native. The problem for me is that it is just a clunky interface that slows down the process of doing things (e.g. waiting for another mode to open for the 2 different control panels, WTF?). Some of the things actually appear to be time based in waiting, because I have a really fast setup hardware-wise and it should "just work" as the other virtual machines I've tried do.
I'm not a big fan of the Mac OSX interface either, but at least it appears smooth when you stick an SSD in an old Mac. I use Mac at work with Windows 7 in a virtual machine (VMWare) (I also use linux on servers) and am evaluating Windows 10 with enterprise deployment in mind. I wonder if the author of the article actually clicked the start button or tried to type much in the new integrated search bar of Windows 10. I mean things like this -- Firefox works well, but if you try to set it as a default application Windows appears to freeze for half a second as it loads some weird "default application" selecting application that is like it is part of a completely different OS that has to load with it.