For all the mac users who have been lusting to put that MS Word machine to good use, wormhole is the ticket. Very simpe to set up, very stable, and it sounds as good as the plugins/hosts you're using.
The way the manufacturer chose to implement the plugin leads naturally to an inability for one machine to recognize and automatically configure network resources. Which also means you'll need to save at least two files for total recall. One for your main sequencer, and one each for each remote VST/AU host. But it does lead to amazing amounts of flexibility. FX Teleport is much more elegant in this respect, but it is also more expensive, although still very cost effective for what it does. But Wormhole is only $25 for an unlimited amount of networked machines, mac or pc! What was Adrian thinking?
You can use any combination of WinXP PCs and OS X Macs (nope, sorry no OS 9 version). For example, my system consists of a G4 Mac running OS X 10.3.5 and Logic, and a Pentium 3 PC running Xlutop Chainer and VSTi's and VST FX. I use WormHole to stream those VSTi's directly into Logic's mixer. But you can use, for example Cubase on a PC as your primary sequencer, and VStack on all secodary machines. Or Digital Performer on a Mac, and your Granted Rax on a second Mac with other AUs or Mac VSTs. Its much better than Cubase System Link. And the only hardware you need are the audio and MIDI interfaces on your main machine! (which you probably already have.
Currently, MIDI is not implemented in the system, but according to the manufacturer, it may be coming in V2.