D+ is what makes Comodo very strong and one of the top firewall along with Online Armor. Just go over to Matousec.com and see for yourself.
Gizmo criticizes the Matousec's tests. It's a technical reading, but seems fair (
http://www.techsupportalert.com/content/matousec-personal-firewall-tests-analyzed.htm).
Others point to an interest conflict on Matousec's tests, reducing their independence (?) (
http://smokeys.wordpress.com/2008/04/20/matousecs-firewall-challenge-wrinkle-conflict-of-interests/).
Leak tests are popular mainly because they are very easy to perform: you simply run a program, and it tells you if it passed or failed the test. However, life is not that simple, unfortunately.
The primary goal of a firewall is to keep hackers out of your system, that is, prevent
inbound attacks in the first place. It's astonishing that many firewaller "testers" only focus on outbound protection, completely ignoring the inbound part (which is absolutely vital). It's like they assumed it worked flawlessly in case of all the products, which, unfortunately, doesn't seem to be the case, really.
Next, outbound protection is of course also important, but so called
leak tests are not everything. There's a myriad of other things that a decent firewall should do, and which are usually not assesed by these tests. All I'm saying is that testing a firewall is a very complex task and focusing on leak tests is a gross (and inappropriate) simplification.
XP users can disable Avast BB since its still needs to mature and D+ is stronger all day long.
Hmmm... I won't disable it.