Because of the smaller movements of the build platform closer to the the-2center, objects printed closer to the center will have a finer resolution.

I think this has been the major reason that polar coordinates have been unimpressive. Speed variation and resolution variation based on radial distance.

The whole multi-print benefit is a rare application, and can be almost approximated by a multi-extruder head cartesian bot, since it would only need to accelerate and decelerate once per motion.

All this criticism aside...the fact that someone thought to do this and followed through, is awesome. I really like the work.