From personal experience privatefirewall is a terrible program.In fact the worst piece of rubbish i ever installed.Use comodo firewall 5.12 which is a far better firewall.Or use online Armor which is another superb firewall.
Each to their own ........ PF is an industry grade firewall that is used on servers as well as desktops, and is very highly rated. Perhaps you just didn't understand the program and how powerul it is?
I wouldn't touch Comodo or Online Armor, based on my experience and that seen on the 1000's of machines through the workshops .....
As it is this thread is about Private Firewall, not Comodo or Online Armor.
Fact is if correctly installed Avast9 and Private Firewall work perfectly on Win8 and provide a very high level of security.