I have and use a 50mm 2.8 Apo-Rodagon and a 90mm 4.0 Apo-Rodagon and love them, especially the 90 for 6x6. I was mulling around the idea of getting an 80 F/4 for 6x6 prints larger than 16 x 20 but since I already have a 90, is there any real reason to have it?

And what about the 80 F/4 Componon-S compared to the Rodagon Apo 80 F/4?