Hello. I have a Nikon N80 that I use for family, portraiture, travel, and sport photography. I am satisfied with it, but am concerned about its build quality and longevity. BH Photo sells a new F100 for $750. I suspect I will want one later, when it will not be available new. What benefits are there to the F100 compared to the N80? I understand the F100 is a superior build, but what about the electronics, image quality, etc.? In short, is the upgrade worth the money? Thanks.