I too was looking for a good 180~200mm focal length, and quality was more important than speed. I intended to use it on full frame Canon, Leica and m43, so especially with the latter center quality had to be very high because the pixel density would demand it.
I have had a micro Nikkor 200/4 AI ever since it came out, and it is decent, but not spectacular. The best lens I tried was the Leica 180/2.8 APO, but I didn't want to sink that much money into it. The Elmar 180/4 and non-APO 2.8's were just not good enough, and neither was the Nikon 180/2.8 ED, both AIS and AF. The Canon 2.8 wasn't up to it either, besides, difficult to use on any body except the Canons. Most of the f/4 lenses weren't up to it either. The 180/3.4 Leica was great at infinity, but lacked close focus and wasn't as good close up anyway.
There weren't any Minolta lenses readily available for me to try.
Finally I settled on the Voigtlander 180/4 Apo Lanthar, which is tiny, focusses almost into the macro range and comes the closest to matching the Leica 2.8 APO. Mine is in a Pentax mount. No zoom I tried, including the Leica 70-180/2.8 APO matched it. I'm happy.
Henning
Henning