I have been using Sygate for several years, and have found it to be very stable; with many good features, such as logs, backtrace and who-is functionality, it certainly serves the purpose. An added benefit is the ability to manage permissions by application, which saves time when beginning to use it.
According to Shield's Up! when I last tested the firewall, all ports it scanned registered as "stealth mode." Just one thing to note is that Sygate is being purchased, so the status of the free edition may be in question sometime in the future; however, since firewalls do not require constant updating, I do not see this as a significant problem to using it.
Edited by jgweed, 04 October 2005 - 11:10 AM.