I have an opportunity to by a Linhof Grandagon multi-coated 75mm f/4.5 (pre -N). What are the differences between a Grandagon and a Grandagon-N. From a practi cal standpoint, I'm an advanced amateur who's a sharpness nut. But....90% of my enlargements are 8X10 and once in a blue moon I will enlarge to 20X24. Would I see any differences w/o getting the latest "N"? Thanks.