I feel your frustration in knowing that if I were to reprint my negs in the future the result would quite probably be better, but am consoled by the thought that in the future I will have much better (artistically) negs to print. So I make the best prints I can now, they get better over time and I generally don't revisit images because I've always got a backlog of newer and better images that deserve to be on paper more than a rehash of a neg from a few years ago.