The biggest advantage of Unix (read Linux or a flavor of BSD) is the uptime and cost.

Until the most recent version of Windows, Unixes beat Windows hands down on the up time issue. Now you just wish the Windows server would crash so you can reboot.

For the most part an upgrade or security fix did not require a reboot and didn't damage your site or its programs.

Gates and company still haven't gotten it right but it is getting a lot better.

I avoid Micr$oft because they are a target. My interior and exterior networks are Linux server based. My desktops are Windows. My developement PC's are both.

It's not that Linux is perfect, I have installed security patches in equal numbers for both Windows and Linux, its just that ultimately why pay an arm and a leg for an OS when the free (or at least cheaper) OS is equal to that OS.