Well, the real difference in speed would not be seen through the network card, as if both the Zorro and PCI netrwork cards are of the 10-base-T type, then the speed would be the same.
Mediator offers fast ethernet (100mbit) and is the only pci solution at the moment that has this feature, however I really doubt that this is too relevant in the Amiga world, especially if your Amiga will be used for hobby purposes, and I'm sure it most likely will be (like with most of us). :-)
Or let me put it like this. The speed difference is not as noticeable on Amiga between 10mbit and 100mbit speeds, as it is on PC.
