Avira & Zone Alarm, or is Comodo Pro FW a better choice?

I've been using ZA Pro for several years (currently v6.5.737.000), and I'm starting to wonder if it isn't slowing my web experience down. Together ZA's zlclient and vsmon use about 40 mg ram. Sometimes I get the feeling that ZA Pro and Avira PE Premium aren't a good combo.

I was reading the reviews on Matousec's site (http://www.matousec.com/), and while the latest version of ZA Pro (v7) got a great review, so did Comodo Pro, which uses less memory.

I don't think I should upgrade to 7 because I have an older computer, and so many on the ZA forums are having problems with version 7. Matousec also had an advisory about v. 6.5.737.000 and a vsdatant driver input buffer vulnerability:

http://www.matousec.com/info/adviso...alidation-of-vsdatant-driver-input-buffer.php


The question is then, as someone who doesn't mind configuring programs, and
delving into the registry to delete all Zone Alarm and Zonelabs references (thanks to Regseeker), should I install the latest version of Comodo Pro?
Is it really as good as the ZA Pro?

Does anyone know how compatible Comodo Pro is with Avira's AV program?