I was running version 6 on my new PowerBook 1.25Ghz... it was alright, ran a bit faster than my 350Mhz PII. A good solution if you just need it for the occasional Windows-only software (no games though!). What software are you going to need to run on it?
I did have a problem with Vendio's Sales Manager Pro software not syncing with eBay auction listing. I don't know if there was something wrong with the VPC networking system or not, I never got it figured out, every other internet program worked just fine.