@liliana The devices serve 2 different purposes. For those of us with bronchiectasis and/or MAC, our main issue is usually effectively clearing mucus from our damaged airways.
The Aerobika and the Acapella are PEP (positive airway pressure) Vibratory devices. Exhaling through them produces a vibration in the airways that is meant to loosen mucus.
The Breather is a respiratory exerciser, which can be used to help strengthen the muscles used for inhaling and exhaling. It can also be used as a tool to help people recover from strokes and other issues, who need to relearn how to breathe effectively on their own again (such as after a long time on a respirator.)
So usually, a PEP is better, but there may be times, such as after pneumonia, when it might be helpful to use both.
Sue