However, BeOS hopelessly outclasses both in the threads department. Also, the kernel, servers, kits and apps are heavily multi-threaded. The API encourages apps to be multi-threaded. If you've used BeOS on SMP machines, you know how important multi-threading is. Linux really isn't that fast, depending on what you do.
Screens have less visible redraw, apps switch quickly from one to the other.
Not to mention the fact that anything media oriented does much better on Windows than on Linux. The Linux desktop IS clunky. It's very attractive, but the Linux guys need to steal some ideas from the Mac instead of Windows.