Digital BW, The Print

Can anybody tell me in twenty words or less what the advantage 
is of scanning in 16-bit?

I heard one guy say that he can let his assistant scan images in 
16-bit, and have them just set the black and white point, and do 
nothing else. Then he comes in after them and really tweaks the 
file.

This scenario above makes sense I guess, but it sure doesn't 
apply to me. Past that, if you neg is properly exposed, and your 
scanner is good to begin with (Imacon), why would I ever want to 
do this?

When I've tested it in the past, and resampled from 16 to 8-bit, I 
see absolutely no change in the file. Am I missing something?

-Simpleton