A sharp inner rim edge or "bite" isn't always a bad thing. Depends upon the trumpet player. I have noticed that on the more forward jaw trumpet player the inner rim edge does not contact the skin at a harsh degree. The upper lip sorta floats right on the flat rim of the m/piece. In fact he may prefer the sharp bite because he'll get more definition between the part of his lips that vibrate and that which doesn't. The receded jaw player on the other hand is likely to have his upper lip contact the inner rim edge at a much more pointed connection. For him a sharp bite is anathema. It sure was for me. The idea of playing a long lead gig with lots of high notes in similar league (to me) as walking on glass. I don't even like flat rims for the same reason: The flatter rim causes my upper lip to bend more severely at the junction of the "bite" or inner rim edge. Thus I use Al Cass pieces for EVERYTHING I do. All his pieces from tuba to French Horn have a continuous radius from outside the rim to inwards. A well rounded bite and neither too wide a rim contour nor too thin. Just about right. If it weren't for Al Cass I'd be just another run of the mill trumpet player. Or I might even have quit playing except as a hobby. I hate to think of how depressed I might have become had I never found his pieces nor took his brass clinic way back when. Ya know from that angle i suppose you could say that Al Cass may have saved my life. We met back in 1976 over a six pack of warm Esslinger beer. A six pack EACH lol. He always drank it warm God knows why.