I have been playing Bach and Yamaha Mouthpieces for decades and been happy with them.
I am playing on a Yamaha YBB-631S
The Arnold Jacobs is a huge difference.
First i noticed how lightweight it is, first rehearsal was an eyeopener, response is very exact, I get an lot easier down to low F even on a cold mouthpieces.
Response in nice from the low to the high (where a Bb Tuba do not belong) Final it feels nice on my lips.
Well the price is double of my normal mouthpieces I use, however I am happy that I did spend the money.