There is no rule that you must pick out one wine or one beer and drink nothing else for the rest of your life...
So- some outings call for sharp, others for smooth.
Completely agree! Apart from that, there are lenses on the market that pretty much provide both - but they're, at the very least, a lot bigger. I love the fact that the APO-Lanthar is actually pretty compact for what it offers. Superb control, but not clinical, just clean - right up my alley!
For the record, I've completed my testing re. the Voigtländer Nokton f/1.2 and Summicron-M. To my eyes, the Nokton f/1.2 can pretty much be made to match the Summicron-M in most respects; rendering is even smoother, and of course, you have another one-and-a-half stops of light gathering capability if you need it. The Summicron-M is a little better behaved between f/2 and f/2.8, but bokeh is less attractive - furthermore, in most situations, the differences in technical IQ are so small that they may be called insignificant, whereas the rendering advantages are always there. The Summicron-M still is a very nice lens, especially considering its size and weight, but I'm finally more impressed with what the Nokton f/1.2 brings to the table. I may have been too obsessed with shooting that lens wide open ...
As for the APO-Lanthar, that's definitely on my list; I'm, however, still dithering whether to replace the Summicron-M or simply add the APO-Lanthar - or do nothing, considering the merits of the lenses I have. But looking again at the performance of the APO-Lanthar, I really doubt I can resist much longer ...
M