I have tried it but can't recommend it. The Firewall is basically Trojan Trap with a few goodies added in. The default rules are far to lax and should most be deleted before you go online. It even leaves NetBIOS open which is not required for 99% of people without a LAN but is very nice for hackers to attach to.
Poko also received some IP stack errors as mentioned in the thread above.
If you already use one the better FW's I would recommend sticking with that.
I use Sygate but Kerio is also excellent but takes a little longer to configure corectly. Either of these with a good AV and possibly Trojan Trap and you a pretty much set for "most" eventualities.
Just my opinion of course
OLDY