2ndcornetvertuoso said:No proffesional musician should use these mothpieces, the metal mouthpiece is designed to stay 'cool', so your lips stay strong. I bought one of these mouthpieces for my cornet a few months back, and found my playing standered fell very quickly. Sure, they might be good to warm up with since they dont get cold, but you should immediatly switch back after the warm up. I found the mouthpiece got warmer and warmer, and my lips weren't working as well, especially in the higher register.
TAKE MY ADVICE.... DONT BUY ONE! overall they are useless (unless you have an allergy to metal).
I can garentee you they won't do you lips any favours!
I think you might be right about prof(f)essional musicians, but the reality is that very few people on here are and I know of a number of top brass musicians who believe far too much is made of variations in the mouthpiece and the reality is that if you practice hard you will play well on almost anything and if you don't, no mouthpiece is going to solve your problems.
Your very strong view ( TAKE MY ADVICE.... DONT BUY ONE! overall they are useless) only seems to be based on a bit of personal experience. I have been using the mouthpiece for a little while now and whilst my primary aim was to improve the effects of the slight allergy I have to the metal, I have to say that I have not noticed any significant difference and it certainly does not appear to have done my lips any harm.
I would suggest that if anyone was interested they should give it a try. It is only going to cost £10-£15 and if you don't like it save it for carol playing!