Diki,
Korg PA2/PA800 has exactly what you said... touch screen function for the sliders AND physical sliders... so you use what you want.
The sliders on the ouch screen work fine and are big enough to use.

However the physical sliders work in JUMP mode (for individual tracks). I have made an official request (others too) to change that to work in PICKUP mode. I beleive it will be done in a future OS update.

Lee