I see a big advantage to this one, In a machine shop, with a lathe and a milling machine you can do anything, This configuration is not for everything, but certain form factors should work better in a polar config. like this, anything round, cuplike, column forms, human figures, i can see the potential resolution of these forms could be much higher, and faster, your not fitting a roungby artcarpenter - Polar Machines, SCARA, Robot Arms