I have a 1994 Martin HD 28. Owned it from new .It is a F*cking cow to keep in tune. I can pick up any of my guitars and they stay in tune even after weeks of not being played.
The 28 wanders out of tune even when just playing finger style I am at my wits end with it. I live in the North of England. It has been to a Martin approved Luthier - still shite. Incidentally he fitted a Fishman preamp /pickup but it was shite before and after being fitted so I don't attach any blame to THAT. In addition to a couple of old Yamaha FG 180's I've also got one of those Martin "plastic" guitars DCX 1E which is an absolute pleasure to play and great sound. I can pick them up at any time give 'em a quick tweak - and perfectly playable without tuning again (relatively) and they are accurate from one end of the fret board to the other. To use that old motor manufacturing phrase , did Martin ever make "Friday Cars" - have I just got a duff one ??? I can't tell you how pissed off I really am. Does anyone know a top "doctor", (bearing in mind distance /location) someone who I think would need to go back to square one , and see what the problem(s) is/are .