I had one that was a really fine mouthpiece. It lacked resistance for a low baffle, large chamber mouthpiece and produced a big fat sound. Mine was opened up by Mojo to .105 from its original "J.A." or Joe Allard facing. Some months later I changed tenors from a Yamaha to a Selmer and the Reso became very difficult to play in tune. After struggling with it for a few weeks, I sold it and moved on. The mouthpiece was always difficult to center on pitch but the tone was beautiful enough that I dealt with this compromise. I played this mouthpiece for about 6 months and enjoyed it immensely.
My teacher played a Reso that was worked on by Theo and I feel like this mouthpiece is better crop than mine was, a better chamber out of the factory, probably.