I have just begun to learn modeling, and I am starting with MORAY, a shareware program that seems to do a good job. (See my first model - nothing really compelling, but I think it looks cool!)

My question to you modeling gurus out there, is what kind of functionality do the commercial modelers (Rhino, Truespace, 3DS) have that the cheaper ones don't (i.e. Wings3D, Moray). I know two limitations of Moray are a) no extrusion tools and b) no rail sweep tools. Is it just functionality or something else?