Thanks for your reply.

I found some time ago that V4 does benefit, especially the smooth curvature of her breasts by enabling SubD. Otherwise, I was noticing a bit of jaggedness in the shape of her breasts, especially the lower part. Enabling SubD smooths it out to what it should be.

But yeah, I could not see any discernible difference between the Default setting which was halfway between 1 & 2, and all the way to 2.