The problem with the gen3 meshes are all the tris they include. you'd have to pull them all out and rework the mesh into quads for optimal performace across a wide range of uses. A lot of people today animate and render their poser figures in other software for various reasons, so if you want a figure to appeal to that audience as well, you should at least attempt to make it cross-platform friendly, and that requires all quads. I suspect this is why DAZ went with all quads in the Gen4+ models.

It's also more logical for lower and higher res figures, and if you want to allow the figure to be used in games. If you don't want to allow that, then it's not as necessary.

 

~Shane