So for example in this area of your model here:



I wouldn't be surprised if that topology there created a somewhat lumpy shape in that area. Probably not enough for you to notice it just looking at the wireframe or diffuse shaded render, but if you were to make that have a reflective material and then animate it, the reflections would probably squiggle around in that area instead of being very stable, while just exporting a mesh of the original model from MoI and not applying sub-d to it would give you a completely crisp and totally unwavering reflection in those same areas, as long as you got the good vertex normals coming through.

- Michael