@John Naismith
John, funnily enough I have tried numerous AVs including ESET and late last year settled on Kaspersky KIS 2009 because it has a very small footprint which on my low spec Dell business laptop is extremely important. That's despite numerous people recommending to me NOD32.
NOD32 was problematic especially on firewall and HIPs functions and I eventually uninstalled it, much like other security suites that I tried. Mis-identifying windows drivers cannot be dismissed as simple human error, that's really a major screw up for sure.
Whilst KIS has not been issue free, overall they seem to be the best product / footprint / security / price combination, at least for me. Comodo was also pretty impressive and great potential, but for me it still runs like a beta product and their AV database is still too far from KIS or ESET, so I will not look at it for another year until my KIS license comes up for renewal.
In terms of support, getting an answer takes for ever, guides are out of date, also their support site was recently hacked in the US but that was the web devs that screwed up. But since you are probably an IT pro then that should not be an issue.
Good luck.