I replaced my Montage knobs just because they look better however these's an issue with the "witches hat" Genos knobs. They are too tall and not secure at the base. The pot base is recessed too much. This and the knob height cause the pot stem to wobble which makes the fixture become loose. I tried to improve on this using these metal knobs which have a larger diameter and prevent the wobble as they rest slightly against the surface if they begin to wobble.
De gustibus non est disputandum... (there is no arguing about matters)
Maybe I can agree with you that slider handles are nicer on Genos, but knobs are way better on Montage.
To me mainly what's better in Genos is that there are 9 sliders allowing more straight-forward tonewheel organ emulation.
The shape and color is subjective.
Guess it's a good reminder that you can change these out since it's easy to pull and push and also order from parts houses.
Current Yamaha Synthesizers: Montage Classic 7, Motif XF6, S90XS, MO6, EX5R