I agree with all of this...however, from an "outside NY" perspective, the desire to work as much as possible almost requires one to be a jack of all. (fooling most of the people, most of the time). I certainly understand the "specialist" concept...and there sure are some great ones out there.
I enjoy the variety, though. Still, the "playing the trumpet" part is just that. Fundamentals, regardless of the genre. From there...listening and emulating styles/sounds.. huge. With all the varying things I may play, I show up to some things (especially a classical/orchestral setting) and spend the first bit (as I'm playing) listening to the sounds of those around me to "remember" where the heck I'm at and what I need to sound like. hahah. (uh...could you tone down that trumpet for this nice, lyrical passage??)..
Oh yeah...okay, switch mindset.
Tony is the chameleon...er...man...