I have CIS ver5.3 on two Windows 7 pc's (x32 and x64). While I admit that CIS is not an install and leave app, it is quite good once you have the right settings that will suit your taste and how you use your pc. I come to like it as much as I like OA Premium and Outpost Firewall Pro ver7. When I have trouble with either Online Armor or Outpost I always go back to CIS and apply the settings I have saved. My resource eating apps are Autocad 2009 Mechanical, Adobe CS3, Minitab14, SAS statistical software. No apparaent slowdown on them.
The SSL fiasco was a fault of how Comodo overlooked aspects because of marketing. And if a company always keep on focusing on marketing profit then problems will really arise. The practice of issuing certificates directly off the root should not be done but rather as mozilla suggested "use intermediate certs" and "different one for each RA account". I believe there was also an incident with VeriSign in 2001(well not in this caliber though but same proof of issuance of "bogus certificates").
Some interesting links about the SSL issue here: HERE HERE HERE
Comodo firewall is very good especially with D+. I am speaking of the firewall only. Personally I don't like the AV either. Sure there are still others who offer firewall protection for free like ZoneAlarm/Privatefirewall/Rising..etc but hey, firewall is really good and in the league of OA and OP. You will not find that "league" on the Avira Premium Security Suite/ Avast IS firewall..(you can't simply terminate a connection there (also with Privatefirewall you'd have to use a 3rd party app like ProcessHacker)..
A first time user especially when coming off from say, Online Armor firewall will definitely be confused with CIS. Even in the rules creation. But as any "new" thing you have(not of the same brand say, mobile phone --say from a Nokia 3210 to a Sony Ericcson android phone) you have to let it grow on you to see wether it's a keeper by your standard or not.
This latest version of CIS has been improved. It's now lighter as compared to ver4. Used ver4 for a month on a test XP pc and went back to Online Armor Premium. Now it seems they are both light as Outpost Pro ver7. Some interesting discussions here about CS ver5.3 HERE
Just my two cents here.