We've been recommending Vipre for over a year now (became a reseller a few months back). Out of over a hundred customers that have installed it, we've only had three customers get an infection while protected by it. While our customers that have gone back or to with McAfee/norton/kaspersk/avg etc... It's not uncommon to see them a couple times a year.
We've been very pleased with Vipre and recommend it highly.