You bet! And there are other factors as well.
The mouthpiece rim profile is defined by three main points, the outer diameter (OD), high point, and the inner diameter (ID). The alteration of any of these three points will dramatically change how the rim feels.
How large or small a mouthpiece rim feels depends heavily on your anatomy including your dental structure and teeth position and your muscular structure. We've seen a huge variety of situations and the same mouthpiece doesn't feel the same across all of them.
Finding a rim that fits your facial structure and provides the confidence and response is our goal.