I picked a fairly stark (and convenient) B&W subject to make the effects of chromatic and spherical aberration easy to see. The shot is Nikon D700, 105mm, f/4.0 @ 1/60s using on camera flash for fill.
The Micro Nikkors are highly corrected to control chromatic and spherical aberration. What we see here is, I think, a pleasant bleed of black into the white background, with no hint of chromatic aberration or geometric distortion. I must say that even compared to the Leica-M 90mm f/2.0 Summicron and Zeiss 180mm f/4.0, my pre-digital portrait workhorses, the transition from dark to light feels very smooth, despite the Nikkor having only a seven blade diaphram.
More serious tests to come, but this is encouraging.