I had Ron Coelho make me a .110HB with a 1/2" longer shank for my 12M; he was right in stating that contrary to popular wisdom, the mouthpiece didn't need to be a large chamber. The high baffle really woke up the upper octave without creating intonation problems in the upper notes on the LH palm keys. about 6 months ago I bought a really nice Yanagisawa B-6, and with the mouthpiece almost all the way on the cork, it plays well in tune on most of the range, but the high notes tend very slightly sharp, and a a little shrill. I talked to him about a rollover for the Yani, and he thought it might warm up the tone overall. Anyone have any experience and opinions with these kinds of horns and mpcs.Thanks.