An interesting topic.
As I only really got into trying to play chromatic harmonica within the last 5 years, I knew from the outset that to try and be able to play every key on the one chromatic was not a realistic goal.
I would love to be able to play jazz, but my background and passion has always been the blues. I started out with diatonic harmonicas back in my early 20's some 40 plus years ago.
Now at 67 I know my learning time is limited. What I'd like to achieve and what's realistic are two very different things.
For the most part, I've been playing my chromatics in 3rd position or Dorian mode with very little use of the button.
To this end I acquired CX-12's in A, D, G, C, F and Bb
Had I not done that, I very much doubt I would have persisted with chromatic harmonica playing.
Now it has its claws in me all I want to do it learn more!
I really wish there was someone I could have lessons with here in Australia, but I'm very much self taught.
I was really pleased with myself once I'd mastered "Big Dave & the Ultrasonics" track "Letter From St Louis". Thanks to Javed, I've been working on Rick Estrin's version of Harlem Nocturne which is almost there.
If I can master a few more pieces, that will be more than enough for me