The bandoneon has several advantages, both real and potential, over accordions and concertinas.
As a large concertina, the bandoneon is fairly compact, no bigger than 25cm x 25cm, and weighs a very manageable 5.5kg.
Far more comfortable than an accordion, it is not strapped to the body, and so saves the back from strain. This means the torso is free to move and allow greater bodily expression in playing. This is important as different postures can help to acheive different bellows effects and consequently different musical effects.
The bandoneon is better balanced than an accordion as each end of the instrument weighs the same and both ends are used to pump the bellows, as opposed to accordions which are only pumped by the left hand. As the buttons are on the ends of the instrument, not at the front, the position of the arms, particularly the elbow and wrist, when playing is more natural and comfortable.
Balance is also greater on the bandoneon than on concertinas as the pressure point, the hand rail, is located at the centre of the instrument rather than at the back. This helps to make bellows handling easier and smoother. The larger size of the bandoneon allows for a greater musical range than on a concertina making it possible to play over several octaves without having to modify or adapt the music. The bandoneon is also more comfortable to play than a concertina thanks to the larger sized buttons.