I have been using Linux on the desktop at home for years. I do have a VirtualBox with XP in it for the rare times I do need Windows at home, which is not very often at all. When i use a Windows PC at work, I find myself missing the "always on top" button. It's such a simple feature, but it's so useful! (Back in the days, Nvidia bundled a tweak with their drivers that adds the "always on top" button.) Also, direct access to USB devices is much simpler in Linux. (On Windows, you need to find or create a custom INF to use Android development software. On Linux, it just works!) And not surprisingly, the Windows command line is not very good at all (no tab completion, limited width) because most Windows users just don't care about it!
I read that Windows XP SP2 and Vista had a deliberately crippled network stack "to slow the spread of viruses". It wasn't very effective at slowing viruses, but it did work well at slowing down legitimate network programs. I don't think Windows 7 is affected by that, but I'm not sure.
One thing that Linux did well was audio. Getting bit perfect audio output is very easy on Linux, not as easy on Windows. The problem is that some developers saw the mixer feature in Vista and decided they want that on Linux as well. Just treat the digital output of the sound card like the high speed serial port it is and the analog outputs as DACs (with variable attenuators afterwards) attached to those "serial ports". On my PCs, I use plain ALSA and forget about the PulseAudio or dmix junk.