I used to have quite a collection of horns, and was one of those guys who rarely showed up at rehearsals with the same one. My friends were suitably impressed
, but I found my ensemble playing suffered while constantly switching horns. I believe you have to "learn" a trumpet, and play on it regularly to get into the groove of the horn. All trumpets have personalities - notes that need to be favored, techniques that are easier/harder than on other horns, mouthpiece issues, etc. The more familiar you are with these quirks (to the point of not having to think about them as you play), the better you'll play.
As I said earlier, I've narrowed my stable down to two good Bb's, and the rest hit the door, bought by someone who wanted them more than I (including my '55 MV Strad, but that's another story). Of course, I still have other trumpets in various keys, a couple of cornets, and a flugelhorn, so the cupboard's not bare. But when I know I'll be playing Eb, for example, I'll dig that trumpet out and refamiliarize myself with it for weeks before I play it in public.
Anyway, not to offend any collectors out there, but the point I'm trying to make is that horn-hopping is not the best way to build a good playing reputation. I decided I didn't have the willpower to resist playing my collection in public, so I got rid of it.
