One last thing - PIV and an '060 on the 2000 will only save your behind up to a resolution of 1024x768x16-bit. Push it any further, and Z2 rears its head bigtime...
And actually you can't do _much_ better resolutions with Zorro III either. They are pretty limited in today's standards. But if you have PCI gfx card, then you can really go further. I for example have no problems using 1600x1200x16bit screen with my A1200 with Mediator and Voodoo3.
Otherwise Mediator setup feels pretty much faster with other things too. For example networking is much faster than for example my friend's A4000/060/Zorro system.
For raw performance I think Mediator is the best today and VERY cheap with expansions. Only positive argument for Zorro3 machine is its elegancy in certain issues (like scandoubling with PIV, soundcards with DSP for mp3 playback...), but for raw bang per buck Zorro can't compete at all anymore.
One way is to get both on the same machine... I have MediatorZIV and ZorroIV busboards on my a1200. That way I can have fast gfx-card, network card, USB card etc in PCI, but also have Delfina Lite soundcard on Zorro. Of course it would be better to have Zorro3+PCI on A4000, but that is simply too much money for most of the people nowadays.