Xenar and Xenotar glass.
I got myself two Rolleiflexes last year both 3.5, one an MX EVS and an E model.
I have a few Hasselblads and more than enough lenses for them and also have my late fathers Super Ikonta C with the Opton coated lens.
So I have just spent three days in the darkroom doing prints from all of these cameras. The images from the Rollieflexes are beautiful, I am very very pleased with contrast and sharpness. I have a 4x5 Omega enlarger and decided to enlarge a portion of a Xenar negative, focusing with an upstreched hand was very hard as she was almost at the top of the tower. The result is incredible from the age point of view, at 60 myself and the glass older than me the quality is impressive. At least the same as the Zeiss Opton in the Ikonta. I have the same images from all three cameras and comparing the prints from each one, I just love the TLR's results.
So if anyone thinks that Xenar and Xenotar glass is inferior stuff, from my observations from Black and White work, they are very wrong. Now for color work, I have no idea and never will because when I do that stuff it is In a Hasselblad back.
Happy New Year to you all.