I have several piano accordions, bought secondhand purely for the reason that they have differnt sounds - thus suitable for different styles of music.

A straight tuned and a chorus tuned box sound so different, the chorus tuned box has a "big" sound: but there are some things for which the chorus tuned box sounds just wrong. the straight drier sound suits some styles and tunes better.

I also have several whistles, including Low Whistles, for the same reason.

Robin