Keyword "Clients"...
The answer is "Yes", I administer their personal machines and yes I have AV software on their Macs and their PCs. Interestingly, their Macs have never been compromised but just this past week one of my clients had her PC pwned by a trojan horse that forced me to use a boot disk to disable it and get her machine running well enough to run additional scans. What's interesting to me now is that some of these trojans seem to be reverting to the old 'disrupt usage for bragging rights' paradigm than the more recent and subtle 'identity theft' process that has been so dominant.
My point is that for whatever reason, be it lack of interest, too small a user base or simply a more secure system, Macs still aren't seeing as many viable attacks and for at least the last ten years the only successful malware has relied on the user to infect their machines while drive-by attacks still hit Windows regularly.
