Until you have played both there is nothing to compare, we can discuss the differences between digital and acoustic accordions until we are blue in the face… but we can share experiences and feelings to some limited extent.
The definition of heresey to many, if I may… let’s pick the widest gap I can provide… playing a Gola and playing an 8X. Both are top of the hill in their respective camps, but I keep falling to that old Bruce Lee saying:
“When I was young, a punch was a punch and a kick was a kick. As my knowledge grew, a punch became more than a punch and a kick became more than a kick… now that I am learned, a punch is a punch and a kick is a kick…”
To me now, because I own both, they are both accordions and each has their own level of superiority over the other
To answer RTW’s question, the Roland accordions can be set up to do either… play no sound with no bellows pressure or to give maximum possible volume with no pressure and pretty much everything in between.
The bellows can be seen as the heart, lungs and main volume controller of an accordion, it is where expression may be added or removed, but the bellows do not define if you are making noise or music, that comes from your brain down to your arms and fingers to your accordion.