How does Private Firewall stand next to Comodo's in terms of install and resourses?
Super light. The installer is 8 MB compared to 200 MB for CIS. The service uses less than 1K of RAM, while the GUI uses about 19k on this system. With all my rules (3 years worth), the PF install is at about 10.5 MB.
with Private Firewall I have more control.
This seems to me to be a good description of PF. You want to easily block a process from connecting the internet? Go to applications and change existing rule(s) or add one if one doesn't exist. I feel too that with PF it's all about control. With Comodo it's all about trusting Comodo.
Private Firewall seems much lighter to run alongside Avira.
It is light next to avast and 360 I can say for sure. Actually, if you really like 360 maybe this would bring it back into the equation for you. 360 is the a-v I am using. I plan to take another look at the newest avast, which I have on one PC, but I haven't had time, yet. I run PF on 3 PCs here.
Had my ups and downs with PF (all of it my silly paranoias with the exception of Windows processes promiscuosnesses (like svchost and oh so many others like FTP.exe and so on)), but if you learn to cycle through the processes once in awhile to check what you have approved, you can learn to tailor your decisions better and achieve higher security and security that fits your requirement quite precisely. Also, cycle through your Application connections. Check to make sure you aren't allowing anything to connect via ports to the net that you don't absolutely need. I blacked out IE, because I don't use it ever. Also, I black out programs now when I install them or when they ask to connect. If I want to update I can hit the button and answer the pop up to allow.
Best thing about PF, it will help you learn about your system and about securing a PC. It's more valuable that Comodo in that way Also, after time, you will find that you can begin to allow or block behaviors and/or connections more and more only once. Then you can wait to see the result. At this point for me, I know what to expect, and the PF lists are fairly short and easy to look after...
BTW, I like Comodo. If the settings GUI were more visually oriented and then clearly divided between net controls and localized program behavior, I would switch for the extra features. I really like the secure desktop for example...