The out-of-the-box performance of Windows in VirtualBox is very good and usually better than virt-manager (Qemu). You can tune Qemu to great performance as well, but it takes some fiddling. VirtualBox is in general very user friendly.
Guest integration (drag'n'drop, clipboard), USB passhthrough and audio support is also top-notch in VBox.
Guest integration (drag'n'drop, clipboard), USB passhthrough and audio support is also top-notch in VBox.