Well I have just joined the Martin club (can I be in if it's a stencil??).
I've been active in this forum since I took a punt whilst in Mexico on a Conn 16M (which was not a MexiConn - ironically), which I've learn't how to re-pad on (well sufficiently for my requirements anyway), do some general tweaking, and practiced further on a C-melody I picked up. I actually love the sound of my 16M but am wondering how different the Martin will be. Since retiring my Alto 25 years ago (always felt Tenor was my instrument) I am now well and truly hooked and giving the piano a rest.
The main downside of the 16M as far as I can tell is the keywork - I'm hoping the Martin Indiana (OK, 'Olds Ambassador') will have a 'lighter' action, be less prone to keys becoming out of alignment, and give me a greater range of tone. Plus I think the Martins look a whole lot less 'generic'.
The other thing I'm hoping for is that it might well help me get Altissimo up and running. So far I have only managed high F#.