I can understand using one Bb horn for everything Bb-ish, maybe that is even OK when playing in the states. Here in Germany, we use much different sounding rotary Bb trumpets for "classical german" music, lightweight Bbs for lead and more "substantial" Bbs for a lot of other things. Each of the horns has its own "palette" of colors that perhaps overlap a bit. The people that book us demand this and who are we to disagree...........
Many of the members and visitors here have a strong tendency to focus on hardware even if the playing opportunities really don't demand it. There of course are those that do not understand the "bigger" palette available with special instruments like your Harrelson. Even so, that bigger palette comes at a price and I am pretty much convinced that the naysayers mostly confuse the artistic with the economic........... It is easier to trash something than to accept the fact that you would have to save a bit longer before making the next step. Patience is not very high on the list of traits desirable these days. It is a mystery to me that players that have not spent months with an instrument become experts about all of the supposed things wrong with it. I pulled my 1974 Bach C out of the case after 2-3 years of not using it. It took more than a week for me to really get to know it again. I mean, this was my staple instrument for over 12 years! Whenever I read the "experts opinions" it becomes very quickly clear that I have no real interest in the drivel. BS is identifiable immediately. No discussion can be carried out.
Each of the custom horns has specific features. If we ask 1 or 2 questions and get answers, we know if someone is an idiot or not. Copy and Paste generation beware!