I jumped on the "get off Windows" bandwagon early after 4 months of Windows 7 by switching to Gentoo Linux and I have not looked back. At the time, I was upset with Microsoft for deciding to drop mainstream support for Windows Media Center 2005 Edition 4 months earlier than they promised by including it with the rest of Sindows XP.

Now I think that my computing experience is better. No more chkdsk on sudden power loss (ZFS is awesome), no more disk defragmentation, no more antivirus/antimalware scanners, no more hunting for updates, no more inordinate number of things starting at boot just because I installed them at some point and no more yearly reinstalls to purge cruft from the system's registry and filesystems. My experience is that my computer performance improves over time with an OSS OS installed, rather than degrading over time like it did with Windows. It is just so much nicer than what I experienced with Windows.