i have a dr-28h i bought in '87 from a local shop in md. played good and was the best bang for the buck at the time. over the yrs it sounded kinda tinny compared to other guitars so i craved something else and 3 yrs ago i bought a martin 00-15.at the time, the sigma was buzzing from a worn nut so i took it to a good local luthier.a bluegrass friend said get a bone nut and bridge, it will improve the tone, the luthier said get the bridge, so i did. OMG!, what a difference!this is a great guitar!plays well, takes the abuse i give it and never skips a beat.i take it camping and we sometimes play all night into the next day, with all the dew coating all of us and this thing takes it and dosen't change a bit. i use d'addario phosper- bronze light strings and its as good as it gets. anybody want to buy a slightly used martin?