> The Npower mechanism adds numerous interior vertices.
> You don't end up with slivery quads, but you do end up
> with a large quantity of small ones.

You're right, I guess the only real reason to implement this kind of output would be if you got a lot of users requiring either deformable models or subdividable/smoothable models. (Catmul-Clark and Doo-Sabin really mess up those n-gon and sliver faces)