It is may be hard for some to tell, since Comodo AV only gets tested by Fanboys and others who make Videos or do limited cases with no real explanations, and Avast! lets all the world see how they are doing against the major AVs at places like AV Comparatives. Go look at Wilders, and see all the Comodo users there (or even look here) who say "I don't use the AV, of course, but am happy with the firewall and D+/HIPS". One of the Comodo mods posted at Wilders recently about not understanding why someone there tested the AV by itself, since he had never heard of anyone using it like that before-only as an accommodation to the firewall/HIPS. Defense+ is a HIPS, not an AV, so should run fine with most AVs and is reported to do that in most of the forums.