I'm not speaking from experience here as I don't own a very high res. monitor, but not so long back I was reading a particularly eloquent question from an American lawyer, who was talking about future proofing images and therefore his reason for using a D800, even though he's no more than a keen amateur photographer. The gist was that when high res. monitors become the norm, and it won't be too long, the difference in resolution between something like the DP2 and DP2M will become very apparent on screen, never mind when printed to a decent size. I'd never really given it much thought, even though I now own a 2M and used to own the 2, but it does make sense. If you end up with a 30" high res monitor, or something close, you'd expect to see the difference clearly.