I am amazed at how sharp these Copal-style lenses are compared to, say, the regular run of Nikons, etc. Even more useful for the DSLR user are the barrel-shaped enlarger lenses. These are incredible lenses, such as the Schneider APO 80mm Digitar Componon-S f/4. It is almost as good as the El Nikkor APO 105mm, which IMO is the single best lens (or most-used) I own. There is, as you know, a whole world of these lenses out there, many going for peanuts. I wish there were a master catalog of all the different formats of each type.
Then again, in my next booklet I look at the 3 Otus lenses and the 135mm, and those are just incredible performers. Some say the Otii are too "clinical" of lack any saving-grace distortion, but my view is that they are empty canvases, waiting for us to pour in the style we are, if we have any in the moment. Don't blame it on the lens for being pristine.
Here is one with the Otus 55mm.