Thanks for that it does help. Your link to the other thread doesn't seem to work. I am talking about professionally. At the moment, I am just doing part time local portraits and some editorial but I need to have the speed of digital processing.
If I understand what you are saying the D100 does render the colour depth needed for your workflow, even if you cannot see it initially. When you say you send the image to a lab for a photographic output I assume you mean that you transfer a digital file for them to process in PS to meet the clients needs and not for them to print out.