It's more the Windows overhead that could be little easier anyway: no antivirus or spysweepers to buy, install or manage, or worry about conflicts, or setting up a secure Windows install, and then those occassions where you have to reinstall..
I didn't pay for any of this software. It's all free. Similarly, I installed it once. No maintenance involved. It updates and runs in the middle of the night, when I'm not using the machine. So where's the downside for me?
But, I think you probably have your stuff pretty tight and down to an efficient maintenance schedule. It's more the average Joe, Jane or Grandma Sue user who sucks wind on security.
The average Joe should check out the
Microsoft Anti-Spyware Beta,
SpyBot Search & Destroy, and
LavaSoft Ad-Aware SE Personal Edition. All free. The MS tool is completely automated.
Then there's the business user - usually an exec or laptop user - who seems to find a way to get infected every month or two. There's quite a bit of overhead in corp technology spent on keeping it as productive as it is, still stuff gets through and even if it doesn't that's money that could be spent on better things..
There's literally no distinction between these sets of users, given the sophistication of the available tools.
It updates and runs in the middle of the night, when I'm not using the machine. So where's the downside for me? Not to be too picky, but.. You're still vulnerable to exploits which spread rapidly - before your nightly update - and to exploits, worms and such, not protected by anti-virus/spyware.