I have a martin 00-21 which I bought in 1957 in Chicago. Still play it. Called Martin to ask if they could recommend an authorized repairman to do the fret job on it. Gave them the numbers and they couldn't locate me. Sort of gave me the brush off. Martin is now a "Corporation". The word is out too that the authorized repair people don't do the careful work required for the older models.
If I were going to advise people to buy a new guitar, I wouldn't recommend Martin today.
I'd go with an individual craftsperson....Taylor, Collings, Larrivee,...
As for 12 strings, I'd take a Guild over a Martin any day.
The old Martins, you can't beat 'em. But I find the new ones leave something to be desired. I also think that their PR sucks.