I guess my question would be... What do you need that v5 has but v4 does not? A P200 would be fine for packet filtering, SMTP proxy, DHCP, and DNS which work fine in v4. The really big benefits for going to v5 (snort, SMTP/POP3 anti-virus, spamassassin, extended logging) all require more processor to run. I guess you have to ask yourself... Am I upgrading because I want something new or because I need the additional new features of v5. You might have to just bite the bullet, and get a used PII or low PIII. They're not all that expensive ~$120 - $180 USD. Both seem to work well on my low traffic home network.
I allready got a Via C3 1000 that does in fact nothing at the moment. AntiSpam, Snort, etc would be nice, but I what I really need is a good reliable traffic accounting system, which does not work properly in V4.
