Well, I got my adapter for the 180mm f/2.8 APO ROM. It was really easy to change, and the stripped screw I was worried about was not an issue. Changing the bayonet was even more straightforward than I thought. I went very slowly and carefully, and it took me about 10 minutes. The lens mounts right on the Nikon very easily. There is slightly more play in the mount than there is in most Nikon lenses, or when it was on Leica, but this is probably to be expected. This is not to say it is loose in the mount...just that if you try to move the lens in the mount, you can do so a tiny bit.
Performance wise...wow. Using the 180 APO elmarit again is really nice. It is outlandishly sharp, so quick to focus and such nice bokeh. I have not had the chance to take too many shots, but so far the impression is great. Metering is spot on using matrix metering (I am using a D3...I entered the lens in as a 180/2.8), focus confirmation is also dead on accurate (though the arrows point in the opposite direction since the Leica lenses focus with infinity at right rather than infinity at left). Using the aperture is quite easy, and the viewfinder is still bright enough to focus at f/8, though in practice I focus at f/2.8 and then stop down. Or just shoot at f/2.8 since the lens is so good that it does not really make any difference except for depth of field.
Ok, here are two fairly boring photos. One through my dirty window, handheld at f/2.8 and ISO 1000 (+.33 EV in lightroom...it was a blah day). Also, the vignetting at the left is from the window, not from the lens.
And this one was also handheld at f/2.8 -- it is at the lighthouse at the western tip of Reykjavik.
This is a 100% crop from the extreme right edge...remember at f/2.8
Sharpening in both photos was very low. I processed them in lightroom and the settings were 14 for amount, .5 for radius and 25 for detail. There is the faintest hint of color fringing in the telephone pole's white plastic wire guard, but I believe that is more from the sensor than the lens. Leica does not tend to exaggerate about their APO correction. I did have a UV filter on it, though I doubt that would make any difference. Anyway, I am very happy to be able to use my lens again, and I look forward to my other bayonets getting here! I am going to try to convert my 50mm f/1.4 E60, so hopefully that will clear the mirror. Unfortunately, I don't think the rest of my lenses will fit...they are all the iffy ones -- 19mm f/2.8, 35/1.4 and 28-90 f/2.8-4.5.