I recently purchased some of the new Geomag Kids rods and panels, and was fooling around with them. One thing I found is that the large holes in the Geomag Kids panels can allow for some interesting combinations of constructions, when combined with appropriate combinations of classic Geomag rods:
Octahedron inside a Cube
. . . . .
Octahedron (classic Geomag, scale 2) inside a Cube (Geomag Kids)
Tetrahedron in an Icosahedron
. . . . .
Tetrahedron (classic Geomag, scale 3) inside an Icosahedron (Geomag Kids)
The links above go to the Geomag Wikia pages for these constructions.