I think its obvious but also worth mentioning that faders and buttons are much easier to use than knobs and rotary switches on touch screens.
Of course i understand why software designers often want to give their products a vintage appearance, but i believe that reminiscence needs to give way to functionality.
Therefor i propose to use faders more frequently in softsysnth GUI. May be even have specialized UI's just for touch screens.
Feel free to discuss
Regards
Coorec
