This DM came in the shop in much worse of a state than the last one I worked-on, though both were certainly "lived-in." The binding was about 3/4 off on both the top and bottom, the top behind the bridge had bellied quite a bit, the bridge needed a second reglue (the first one didn't look like a professional job) and there was/is top distortion anywhere on the guitar where there's no extra bracing (which is a fair bit of it, considering the reduced bracing on these).
Repairs included that bridge reglue (and slight relocation for proper intonation), a fret level/dress, binding reglue jobs, K&K Big Twin pickup install, and setup. After work it's like that other DM -- a powerful, warm, woody-sounding dreadnought with a lot more going on than you'd expect from a guitar of this caliber (just a bit below the level of a Guild D4). It has plenty of volume, the neck feels like any other modern Martin -- quick and almost electric -- and despite the evidence of tons of shows under its belt, it hasn't given up in any severe way.
The line in front of the bridge shows just how off the bridge was glued either at the factory or after its first "reglue" job.
No, the back isn't arched -- the satin finish has just worn gloss where it came in contact with the owner.
The K&K replaces some sort of random undersaddle pickup.