I am currently playing the ZO copper bell (only 2 days)... My other trumpet is a Martin Committee (new, brass laq, med bore) ,,, Playing: quite a difference between the two... the ZO has a phatter, darker tone and is easier to play throughout range... I have not pushed the ZO with the band yet, but my impression from playing it for a couple of days is the Committee will cut through easy(er) in the upper register, I say this because the ZO's tone is mellower up there,,, I will see about this over the weekend... the ZO is slotting better than the Committee (for me). The increased air flow requirement is obvious at any volume. The ZO valve placement feels natural and the valve action is superior to the Committee. The slides, joints, bell, everything fits well. It is a beautiful horn... Most impressive.