Here's a 3D variant of the Polaris. It's twice as fast and the control throws are such that it'll spin faster than the fastest lawn dart, a rapid application of full elevator will cause it to snap (but constant full application will get you about two tight loops before it starts to tumble), and full application of rudder by itself will cause a barrel roll. The ballooning with rapid power changes has been minimised, but not eliminated (I do not think this top mounted engine design will allow it to be totally done away with).

This was done all within the proper physics envelope. There are no cheater parts or any fudge factors in the physics. All weights were calculated based on the volumes of the foam components and the CG adjustment was done with ballast added to the nose. So this is a design you could take out and build in real life and expect similar results.

This AV as well as the original 3D model are by Doug Kaye (DHK79)