I became curious and started to google the web for information. For the past seven years my trusty, everyday mouthpiece has been the Bach 7C. I've got a Bach 10C in my case for some unknown reason and it's been a reassurance of sorts, but I've never actually used it (and owning it wasn't the result of a conscious decision!). The Bach 7C was part of the original purchase and I never thought another moment about whether it was the right one for me or if something else might have been better.
In the search process I discovered two websites by James Donaldson, The Trumpet Gearhead and The Schilke Loyalist. Here I found advice on choosing the right trumpet, cornet, mouthpiece, mute, and several other dilemmas facing the trumpet and cornet amateur. Donaldson acknowledges that many trumpet players begin their study with the Bach 7C mouthpiece. Sound familiar? When the student is ready to advance beyond the beginners level, he highly recommends Schilke mouthpieces and in particular, the Schilke 12A4A as a strong and satisfying "everyday" mouthpiece. So that's what I purchased.
I actually bought a couple of Yamaha mouthpieces with which to experiment, but I haven't found the time to play them yet, because the moment I put the 12A4A in my horn I was smitten. I haven't had that kind of revelatory experience in a long time. I suddenly could play stronger in both the lower and upper ranges. It was visceral! I find that I'm not missing as many notes as I usually do (particularly in the upper ranges), I don't get fatigued as quickly as I'm used to, my sound is brighter and bigger, and I'm hearing myself better. It's a phenomenal change.
I haven't had a chance to do any ensemble work with the new mouthpiece yet, but that will happen soon. In the meantime, I'm beginning my horn life anew and hoping to proselytize on the subject of mouthpieces. This is too good to keep to oneself.