There are many security products out there and if we account for detection, prevention and cure each one implement them at various degree.
AV comes in many flavors and are bundled in suites too.
There are plain AVs with no real-time scanning functionalities too.
There are AVs that cannot remove all kind of threats too.
I guess that we can all agree a the common denominator of AVs is
detection.
HIPS on the other hand focus on
prevention.
In my own experience I ran my system with only CFP for two months and I got no
badware though this outcome was a result of my habits, security practices and I guess proper CFP usage.
During those two months I usually relied on CFP whitelist, Trusted Vendors and submit to comodo for analysis responses (I guess we can agree this is a sort of detection).
This way I was able to run trusted software without issues (meaning software I trusted or trusted by Comodo).
When I found software I did not know or Comodo did not analyze yet I relied on HIPS alerts in order to check installed software behaviours.
Still there were some cases an AV would have come in handy when I had to decide if some software was able to run/install kernel drivers.
If i didn't know much about that software I simply denied those requests and uninstalled that software.
I installed an AV again though because even if CFP features provided me a good security, AV detection could make my life easier.
Anyway I think that possible CFP3 future evolution and enhancements could compensate my need for AV detection.