Pari Red Cup Experience

I have both the blue cup and the red cup from Pari. I just tested the red cup with a 3% saline to see what it is like and right away I noticed that it is not as harsh when nebulizing, compared to the blue cup. I am interested in anyone's experience with this. I understand the Red Cup has smaller modules that can get into the deeper part of the lungs and it is slower than the Blue Cup. Is that why it does not seem as harsh as the blue? Blue is supposed to be the rapid mist and you spend less time doing it. My Doc has no opinion the this and I don't think he was familiar with this at all.