Bear in mind that a lot of these programs/toolbars rely on user feedback to the manufacturer of the toolbar.
This is only as good as the intelligence/integrity of the user.
McAfee's is the only one I've used (long ago) and my impression is that there is nobody at McAfee actually monitoring the user ratings, much.
Don't rely on them. They may provide a guide; that's all. No better than, say, a Cnet user review.
I rely on the Avast Webshield, and NoScript in my browser. Works fine.