They are as secure as you configure them to be(the site doesn't give you a firewall it just gives you rules for the one you already have ) , the site i posted above does the typing for you (saving a lot of time) I would suppose with the know how you might be able to add/change some rules yourself that improve it . I personally don't have the want (at the moment) to learn to hand configure ipfw and when i do i will use the preconfigured one as a template (because one should always work smart, not hard