Bought two of those which varied much in quality but both were pretty bad - one was almost usable. In the lower register they played pretty well, nice response and quite good tone quality but around upper g and upwards, the tone quality was terrible - thin sound with some high-pitched resonance (or buzz) on the verge of cracking. Might have something to do with that the facing was a bit uneven. Maybe if refaced it can become a good mouthpiece.
Tested on a Selmer SBA in excellent condition.