Well I have a few macs, but all without serialports, so I have to get some usb adapters then.
But I have used this kind of serial servers before, when I attended school we used this devices to communicate with old PLC systems, but then we used pc (with routing software) to serial server, not serialserver to serialserver. But this should not mater.
But I'll check around and see if any of the supplier my company uses has this kind of equiptment, in that case I can borrow a pair to test.
It would be interesting.