Any User Comments On This?

I always recommend against paying for any software firewall since you can get the same (or better) quality from freeware solutions. The free version of this one seems to do less than other options. I don't use Vista, so I don't know which ones are compatible with it. matousec.com has a lot of good information about software firewalls, including ratings. The one you linked to isn't even mentioned, so I'm skeptical.

If you are planning to use Windows 7, I would at least wait until the final product is released. Until then, we won't be certain about what might be necessary.

There are some who hang out in this group who are totally against software firewalls in XP/Vista. You can check out their advice as well, and decide what's best for yourself. You can find their comments in the longer threads from this group over the past week. Here are some of the links they suggest:

Excellent. Go for it! (Free versions available).