After spending quite a lot of time over the last week studying my contact sheets and making notes, I can't see how anyone could reasonably work and edit their photos just by looking at their negatives. I know several people have posted in this thread as such, but I just don't get it. With contact sheets, you can sit on the sofa with a sharpie and a glass of wine and really get some thinking and learning done.
I suspect that the people who work exclusively from negatives are underperforming their potential as photographers.
My two cents, y'all.