Check out this milled PCB that Per from  Zapro.dk Blog has made. If you think those are small traces and fine work for a milled PCB you are right. Not to mention the vias are plated through. This board is for a 5X5X5 LED cube that you can see in action here. This was done using a Protomat and a Minicontac II. You can see a Protomat in action here.
