"Unlike other building toys such as Lego, Construx feature beam-like pieces of varying lengths that snapped on to cubical connector knots in order to build large shapes. These are relatively secure even though no nuts or bolts were used. Panels allowed assembly of flat surfaces. Hinges, motors, wheels, and other movable parts expand the number of different shapes that can be built, and make moving creations possible."
I had two motors and could build simple robots. Due to the long size of the pieces, one could build truly gigantic things. I build really big helicopters, AT-T Walkers and whatnot. I played with this much more than with Lego. Also, the pieces had a bit of a 80ies future style look, which fit well for all the Sci-Fi things I was building.
But maybe I'm not :-)