I have used Webroots for years, and also advised many of my friends to purchase it. The product has worked OK. It does let some viruses through. When I loaded Avira on my system and scanned it found several viruses that Webroot Spysweeper didn't even know existed.
But my real complaint is there service. After problems with the backup option of their software (which has never worked by the way) I called the support line. Waited on hold for 30 minutes, only to be passed to 2nd level support after waiting another 20 minutes. Long story short, they couldn't fix the problem and said they'd have an answer in a couple of days and email me. Since then I've received no email, and worse my account has been disable and I've lost my subscription. Multiple emails to support have yielded nothing but closed cases. I submit a ticket and they just close it.
I WOULD NOT PURCHASE THIS SOFTWARE. ITS QUALITY IS NOT MEDIOCRE, BUT THE CUSTOMER SUPPORT IS PATHETIC (I.E. NON EXISTENT)