I use an older version of Zone Alarm Pro (v4.5) because all I want is a great firewall. I don't need features that are covered by my antivirus. When they started adding all that crap to it, I stopped upgrading.
The pro version has an advantage over the free version in that I can import/export settings and add bad IP's to a block list.
Pro version also has some pretty good ad/popup blocking for IE that was important on my other pc when I was using a very light homemade browser
as my main browser.
It blocks what it should and doesn't block what it shouldn't...it works. What more do I need?
My new pc came with Norton pre-installed. What a nightmare! Every time I tried to use IRC, it would end up blocking the servers after the standard scan they do....even after telling Norton not to do that. I think I got rid of it after a max of 2 weeks of frustration.
In order to make more money, they added more crap to Zone Alarm. They didn't improve the firewall itself. That remained the same. What you get when you upgrade is stuff they have convinced you that you need, even though you probably already have it covered in other software, and maybe the other software is doing a better job of it. It's a sort of manufactured paranoia in order to boost profits.
When you have an already perfect product and there really isn't a way to improve on it, the only way you are going to get your customers to upgrade is to add new features.
How do you 'improve' the best firewall? By making it a combo firewall/antivirus....
But is that really an improvement if it's not the best antivirus?
No. You end up having to disable all the new antivirus stuff and running a good antivirus any way. Not disabling all that new stuff will make it conflict with any antivirus you decide to run.
So it would be pretty stupid for me to pay for features I am going to disable.
If you plan on relying solely on Zone Alarm as both your firewall and antivirus, then the upgrade or purchase of the latest version is worth it. But I don't have enough confidence in their product to trust it as my antivirus. I will let AVG handle that part of my security.
As far as Zone Alarm's firewall goes though, I love it.