Thanks for the update Rob. I've just scratched the Unibrain Firewire800 card off my shopping list for now. I have a RAID1 box connected to a Windows system right now with USB2 which I would have loved to connect with FW800. I'm not willing to put up with flaky access to the box though.

As for Drobo, I still love the idea, but I'm hoping they come out with something new that addresses the (low) speed issue in a meaningful way.

Whatever you do, don't try to put Leopard (10.5) on that PowerMac. While a lot of things work great with Mac OS, I do not recommend Leopard for anyone with a PowerPC system. Too many stability issues and absolutely nothing terribly worthwhile over top of Tiger (that actually works well on a PPC system anyway).