I'm a sharpness nut with top-end MF and LF glass. I also have the 300/9 M, my only non-German lens, and it just doesn't compare in sharpness to my 150/5.6 super symmar XL and 210/ 5.6 apo symmar. If the 300/5.6 apo-symmar and apo-sironar S are as sharp as the 210/5.6's, they'll blow the Nikkor away. The penalty, of course, is carrying the huge 300/5.6 not to mention 4x the price. The 90XL isn't as sharp as the 150XL or 210AS, but still easily beats the 300/9 Nikkor. If you look at the chromes taken by the 300/9 (I use velvia for landscapes/architecture), they look sharp by themselves, but compared side-by-side to shots taken w/ the big plasmats and you'll easily see the difference. My sharpest LF lenses rival my MF lenses while the Nikkor can't come close. Bottom line is you get what you pay for. With the 300/5.6's, the MTF's are very high at the center of the image circle, and if you're shooting 4x5, you're using only the sweet spot of the lens. I haven't seen any MTF's for the Nikkor M. Still, I use the Nikkor 300/9 due to its diminutive size. If there were a 300mm lens the size of a 210/5.6 apo-symmar and equally as sharp, I'd buy it, even if it were 3x the money.