The fact that it monitors two way internet traffic and will block any software not on its +ve list from communicating with the intenet is of no use? Seems there are many experts who think otherwise 
Its an extra layer, but its not "a decent software firewall".
You show me any "expert" that says otherwise. The primary firewall should not be on the OS its trying to protect. That is what any expert (which rules out most mainstream mag journalists) will say. The software firewall can be floored quite easily by exploiting unpatched flaws in the OS. Hence, protect the OS with a f/w on a seperate device.
There are scenarios where it is the only option - I know, I support a load of them, mostly Linux servers running IPTABLES. Fortunately, these ones forced to run a software firewall an an absolute minority (probably 80 or 90 max). Guess which ones get hacked, and which ones don't...
so are you saying that the firewall that is built into the anit virus software needs to be better or run from a seperate hard drive or am i just not understanding 
Don't rely on a Windows based firewall to protect your Windows PC (or a OSX based firewall to protect your Mac). Though in a home environment, you are protected (most likely) by the NAT device in your router (NAT is not a firewall), but also investigate any proper firewalling capabilities it has, and use them if available.
If you wish to run a software firewall on your PC, thats an extra layer of security, but should not be relied upon solely if at all possible. There are times when it becomes unavoidable - 3G dongles/MiFi/Tethers are a common one nowadays, so a software firewall can help in these scenarios, as "its better than nothing". Though the built in Windows one is as good as any, due to the way Windows updates itself - a regularly updated one is better than a "better" one which hasn't been updated (I come across loads of PCs running hacked security software, which are obviously quickly out of date). Just don't trust it (any Windows F/W). FWIW, I don't think one particular software firewall is better than another, they all work on the same principles, and configured correctly, allow/block the same stuff, and all are prone to the same failures

Obviously, *ALWAYS* have an On-Access A/V scanner running, and regularly do a A/V On-Demand scan. Same with Malware.