I think bandaging the 3x3 cmetrick is a little silly. Far better to start by bandaging the 2x2, which is a much purer distillation of the concept.
Also, the balls of the 3x3 are not all equal. If you plug a hole in one of the corner balls you can still go around it by doing a 3/4 turn the other way (assuming no other bandages block this movement). That option is not available on the centre ball because it has cogs on both sides.
In my opinion the 2x2 is much purer just because the balls are all equivalent.