Your problem might indeed be a problem of acclimation. Also, you might want to try one of the newer "PRANA" configurations. Monette is now making mouthpieces in a new "PRANA" "slap" configuration. This is a mouthpiece with a slightly sharper inner rim - which allows for more "pointed" attacks.
I play on a Monnete PRANA Bb LTJ trumpet with
Monnette PRANA MF III & B4LD mouthpieces
Shawn Hines
www.shawnhines.com