The Bach 2G trombone mouthpiece has a deep cup with a large diameter rim. The rim is flat and not too wide (neither narrow nor wide). Perceptions may vary with the player and the instrument, but at least in my case (new player with a Bach 42G trombone) the sound I have got is big, but "stuffy" and not clear. Besides, as expected, the large rim diameter requires a very strong embouchure. That is, not for everyone.