Well, the reason VPC 6.0+ doesn't work on G5's is because of the pseudo-endian emulation thing, which was implemented to increased speed. I've heard that VPC 5 does not include this, hence it's slower but may run on G5's. Besides, if people can stand running VPC 5 or 6 on current dual G4's, I think I can safely say I can stand using VPC 5 on my dual G5 if it works. ;-)