Much as I hate Symantec, it's what I typically use. What I've found in a lot of cases is that if I use something different (recently I've tried Kapersky and Panda), some dumbass will either hound me about not having "brand name" AV software, or they'll just install Norton/Macafee anyway (thereby stuffing up their PC), because the stuff I've installed isn't software they RECOGNIZE as AV software.
Seriously. One of those two things has happened to me four of the five places I've tried something different, even after the 5 minute "this is your AV software" lecture.
So, anyway, I liked what I saw from Kapersky. I'd like to use Kapersky. But in my experience explaining to someone that their antivirus product is called something besides "Mcafee" or "Norton" is too damn much trouble.
Were I at a site something more like full time, rather than on weekends when users generally aren't around, I'd probably MAKE them use something else.
Of course, I also have a client where one of the employees broke the antennas off 3 PCI 802.11 cards because thought they were handles...