VMs (Qubes) work like a snap. I typically run 8-10 with various utilities/browsers and wouldn’t even be able to “tell” that it’s running in a VM if I didn’t know any better. The entire OS feels very lightweight and snappy. I also prefer minimal UIs, so that helps a bit. I can see where the UI might “put off” some modern users, as it reminds me a lot of the old CDE interface without the bottom status bar that CDE used to have (I believe Qubes uses GTK-2, IIRC). The included Linux Qubes (Debian, Fedora, Whonix) all work well and provide a “seamless” enough experience, considering that you are always working with multiple virtual machines.
Others in the thread have echoed concerns about the funky copy/paste feature, but it works well for me once I got the hang of it. I sometimes now even accidentally do the two-step copy/paste even when I’m not using Qubes.
Windows 10 in a Qube, on the other hand, is only okay-ish. It’ll get the job done running Office 365, but I wouldn’t exactly call it a pleasant experience. It’s a bit sluggish and will only run in full VM mode, which is a resource hog.
Although I don’t really call Windows a pleasant experience in most cases. ;)