you should look how many useless notes are made by web loggers, in a single minute.
a firewall is made to reduce needless operations while being connected with a computer to a network or internet. logging of all allowed outgoing connections is useless, but it generates operations, even on the harddrive.
a firewall should give the opposite effect by intention.
you can log all outgoing traffic with comodo, too, "allready". but i would not do it.
and often things are just added, so the customer has more in the packet at check out