Kevin my experience exactly, my server at home is used for all my web development work. It runs from one year to the next, does the job in the background I need it to do, with just the occasional restart of Apache when I change the configuration file.
All my published websites are on a dedicated server in a major data centre with multiple data pipes run through different physical routes, UPS and diesel generator backup with high security around and within the centre and fire suppression systems and a maximum of 4 hours hardware repair time. A daily backup is done to an offsite backup centre and I run a mirrored raid system on the server. I do use Red Hat Enterprise on this.
I leave my windows desktop running 24/7 for reliability and find I have to reboot it every few days, where it gets slower and slower, when it comes up with the message, "running low on virtual memory space, creating a bigger swap file" I know it is time for a reboot.
To me the more transparent an operating system is the better as it is just an interface to do a job. Previous to Windows XP, to me, Windows was not fit for the purpose due to the DLL overwriting problems which crashed the OS and mean't a complete rebuild. XP is much better, but I hate the way Vista and Windows 7 hide everything, so you have to go around turning everything on, to actually get the job done you are trying to do. I have found the deliberate limitations build into the "Home" versions of windows means you have to find work arounds and the Business versions are not a cheap OS, even at OEM pricing.
On the security front where windows desktop is an open system it is inherently insecure, where Unix / Linux are inherently secure. Windows has always been a memory and resource hungry operating system although I do acknowledge that Vista and 7 are faster where the use hardware display rendering.
In any monopoly situation, development is slow due to a lack of competition, which is why I welcome the competition in the phone OS market, which is driving improvements and innovation at a fast pace. If Ford had been a monopoly supplier of cars with over 90% of the market I'm sure the Model A would still be in production, as this is the problem with the Microsoft monopoly, you put up with what you are given as there is no realistic alternative in the desktop market, thank goodness we have the Windows / Linux competition in the server and web applications market.