When the 40 Focotar came out, many were ... unsatisfactory to those who were used to the Focotar 2. I was confused over this: why wasn't I getting the results I hoped for with the new Focomat ? Working in a camera shop frequented by some astonishing photographers, I asked one fellow about this. He said his "Parisian photo agency" had thrown out all the 40 focotars and replaced them with 50 Apo Rodagons. And I did too.Well, I SOLD my 40 ! The 50 cam was available then, and I haven't looked back. I did replace the Apo Rodagon with the N version years later, when I had a job to produce a show of 16x20s for a client, from Rodinal and Tri X, and found the new version had better, pinpoint acutance across the field at f/4.0 - 5.6. A pretty severe test, working often at 20x enlargements. Vacuum easel... all that. No difference in making 12 x prints.
Years passed, and now I've got a row of enlargers in the basement. There is an Apo El Nikkor, whose surly disposition is about a full paper grade contrastier that the best from schneider or rodenstock; a handful of El Nikkors from a defunct color sep house in Detroit ( apparently hand picked from Nikon, and just astonishing lenses, the EL Nikkor 50 is as good as the Apo Rodagon 50 ) and a few other examples.
All of this boiled down to this: with the sole exception of the Apo El Nikkors, a new Apo Schneider or Rodenstock are the best you can find, and equalled only by over achievers from Nikon, Minolta or Fuji. And unless you are at the limits of the their designed range, in a perfectly aligned enlarger with glass carriers, you won't see that superiority. generally speaking, the more recent the design, the better the lens. And for every under-performer, there is an over achiever.
For something mundane, like 120 portraiture, or 4x5 landscapes, a c '50s Ektar or '60s Componon is splendid.