Thanks Eckleberg. Played a bit today. I think that answer is that the 1 1/2C is a great mouthpiece, but endurance is probably where the issue lies… If we try to play much above High C for very long on the 1 1/2C, it’s harder than smaller / shallower mouthpieces.

Switched around amongst 1 1/2C, 3C and 3E today a bit. I could play all of them. But it still did seem that above the staff was clearer, less airy than the 3C. Above high C was easier on the 3E, but I have to play that a bit differently not to bottom out on it.

I think I’m starting to get it. I knew each MP had it’s pros and cons, but I think I’m starting to understand the nuances of playing each.