Another "moral of the story" thought here is that it pays to keep up-to-date with what´s out there...new, free, or pricey...if you are really concerned about the security of your system...
...seems like these "top" positions are regularly changing, although the differences are probably marginal.

So, use one that works well for you, and maybe do a supplementary scan with one of the others (but check that it´s a legitimate detection!) from time to time...that should take care of 99.99% of your needs (<--- best rate we´ve had so far )