Comodo is definitely more robust and has more options for the user to control.. but at the same time, its the only firewall that has supposedly passed all 100% of the tests.. Online Armor and Outpost both reached high leves, but only got around 96-98% raiting iirc.. but this is also according the the Matousec site, which lately people have been stating cant be "trusted" anymore.. .. Comodo was very simple for myself to use.. it has the learn mode at first and learns everything that is on the computer.. then after that, it starts to remember your behavior and you dont get to many popups with it.. it also had the option to switch to Gaming Mode.. which for those that are online gamers or love to do LAN parties, i feel this is great.. it supposedly will help stop interuptions and help with less lag and what not...
Online Armor is pretty similar with teh Comodo in that it has the learning mode and what not.. i feel i get more Pop ups with OA Prem though than I did with Comodo... Also.. you have quite a bit less control with OA Than comodo.. for instance.. you cant go in and edit the firewall for the settings for Utorrent as well or easily as you can with Comodo.. with OA.. you just set it up to "allow" and you are supposed to be good.. so whether this is a bad thing or not, i guess is up to the user.. but you can definitely tweak the settings a bit more with COmodo i think..
I havent had much use on Outpost, so i can't compare to those 2.. but.. everything i have read has put it on par with OA i think.. so with either of these 3, you won't go wrong with protectiong your computer i think
Zug