It's a good site, that is true. The problem is that not every AV company's software is tested. Webroot, for instance, hasn't been in that test for quite some time. At the end of the day, I've seen thousands of computers over the last 8 years with the more common AV programs installed on various operating systems and have been able to see (real world and not lab results) the effect they have on machines. Here are my impressions over the last 8 years:
Norton - Newer version is faster than previous years (especially install/uninstall/resource usage), but the definitions are clearly still missing a number of infections that others catch.
Kaspersky - 2015 program is slow and resource heavy. Still seems to be an issue randomly that the registry key gets botched and the keyboard on the machine stops working. Definitions are good and it effectively prevents most infections.
Webroot - Fastest install/uninstall/scan and lightest on resource usage. No definitions to download (cloud based) and can run side by side with other AV programs and cause zero conflicts. Definitions are good and it effectively prevents most infections. Will clean a system without specialized tools, unlike many others.
MBAM - Good install/uninstall speeds. Scan speeds better than most. Definitions are good and prevents most infections. Will clean a system without specialized tools, unlike many others.
ESET - Horrible resource usage. Appears to prevent most infections, but at the cost of system performance.
McAfee - Poor resource usage. Definitions are mediocre, but do protect fairly well. Performance hog is primary issue along with the length of scanning times.
AVG - Install/uninstall takes longer than needed. Scans are somewhat mediocre.
I could go on, but you get the idea... most of the rest are mediocre at best. There are some other really good ones out there, but from personal experience over time, MBAM and Webroot have the top right now. I would urge you to check them both out if you haven't.