it just interpolates. it really works like the mesh smooth in max, only thing is if you work with different smoothing groups it might create gaps. so best thing would be to keep everything smoothing group 1 and then bevel edges (or create an extra edge loop around the areas you want to keep sharp).
oh! that reminds me...when you say "re-inforced edges" do you crease the edges in maya? I've always had trouble getting zbrush to recognize the hard edges in max when exporting. I would export say a cylinder and when it goes into zbrush to divide up, the edges would bevel no matter how many edge loops I put into it from…
well there are a few ways of doing it :) i personally for speed just added a few edge loops to evenly space the divisions, and added a few around the edge to stop it folding in on itself HOWEVER im sure this is not the best way to do it as you end up with a large amount of polys on the edges of things. another way i found…