so, there's probably a really good explination for this, but being that I'm new to all of this, I'm not afraid to ask. :-) Most brands of straights have many different models. Bokers for instance have the king cutter, the injun and others. There are obviously more than I can mention. So... generally, what is the differences in a brands different models? Not just boker but in general? Is it different metal? Just a different shape, different edge, etc?