If you are a NW2-NW2.5, what density can you aspire for from a HT

I am nearly 27 and am planning to undergo my first HT within a year or two. I have a NW2/2.5 hairline with some very slight diffusion throughout. My goal is to fill in the hairline to give it a bit rounder of a shape, but also so that it is more evenly filled, as currently the balding leaves it patchy in some areas. My question is, what is the density look like relative to the rest of my head, after a HT. I am aware it won't be as thick as the donor. Will it have a slight diffuse look to it? Is it usually to thin to lie flat?