Why the switch? It's not because Mac is immune to malware, despite what Apple might have us believe. In fact, the advertising claims that Macs are immune to malware actually annoyed me so much I almost didn't buy the iMac. Then I saw the ridiculous Microsoft ad claiming that a $699 Windows-based laptop was somehow comparable to the $999 entry level MacBook. That claim was so ludicrous, I decided the misleading marketing field was even.
I'm definitely glad I decided not to let the ad annoyances stand in the way of what really amounts to a very good buy. For starters, the 24" iMac runs WoW in full cinematic splendor with no lag even in Dalaran. Anyone who plays WoW knows that's no small feat for even a top of the line expensive gaming rig. So to get that level of performance for only $1800 seemed too good to pass up.
On a new Windows system, it's at least well over an hour (usually two or more) before the system is patched and ready for use. And that just means the beginning of a series of lockdowns - everything from disabling autorun, to enabling file extension viewing, to setting up Internet security zones, to disabling system restore, getting rid of the Windows security center, installing a new firewall, getting the multiple behavior analyzers installed, disabling unnecessary services, installing third-party patches and so on. In the end, bringing a new Windows system online is about a full day's worth of work for me.
On the iMac, in well under an hour I was up and running, having installed Firefox, loaded up the NoScript addon, disabled Google prefetch, and installed Intego VirusBarrier. All that was left was to install WoW, get the latest Blizzard patches, and then run freely through Dalaran for the first time ever without lagging into walls on the way. It was very nearly a religious experience.
The iMac comes with BootCamp preinstalled so with plenty of now unused licenses for Windows XP sitting around, dual booting into Windows as needed won't be a problem. As soon as I get the free day to spend securing a fresh Windows install, I'll finish that task. In the meantime, the iMac has everything I need to be productive (and have fun at the same time).
I love my new iMac.