The Performa 600/IIvx/IIvi is a dog.

Slow, slow, slow bus due to being underclocked. I had a IIvx. I was happy when its logic board failed. (As odd as that sounds)

I turned it into a Quadra 650 and then sold it.

Any complete quadra would cost the same as the board, you could build a really nice system off of that.