ZA is "Old Reliable", it works great with no problems & uses moderate resources.
Well, with a local proxy application,
Kerio does not start it service... first attempt is an error and then, after some seconds the icon disappear from the system tray, although the firewall is running...
Comodo brought me so strange GUI problems... maybe I just use non-standard fonts size... strange...
I've tested Jetico too... I've tryed Sygate...
The old ZA is on it's way... unbelivable.
The best firewall I've used was Outpost Pro (BEFORE they add the antispyware features that turn it into a bloatware).