This is just my opinion, and one based on experience over the past few years. But I do have a question.
I have loaned a few horns out to some seriously good musicians over the past few years, and when they come back, they play much better, in terms of tone and accuracy for slotting. Two players in particular, even if it is a cheap Chinese horn, it comes back just so much better. On one occasion an Eb was loaned, and I watched these two players perform Vivaldi trumpet Concerto for 2 trumpets, one player had a Schilke Soprano Eb cornet, the other my Chinese Eb. On return, he said "That was hard work, but OK" based on that he knew it was a cheap horn.
I have loaned out a few horns - they do not get a bath, just oiled and greased. They have all come back better players on return.
So my question is:
Does something happen to the metallic structure when played well over a period of time that makes it play better?
So buying a 2nd hand brass instrument from a reputable pro gives the horn an edge over the :Brand new: horn from the factory?
Any one else experienced this?