I have a few guitars collected over the years, but my favorite is a Martin 000-15S. The "S" means it has a slotted head. It joins the body at the 12th fret. I have always thought that this kind of guitar has more tone per volumn than one with a solid head joined at the 14th fret. I was happy to hear recently that Norman Blake says the same thing.I think the 000 guitars lost some bass when they flattened the upper bout and made the fretboard two frets longer. Blake also thinks the sound is enhanced with a 12 fret guitar because the neck joins the body at the strongest harmonic. I certainly am ready to believe it. He tends to use ancient Martin 00s, although he has a Martin "D" with a slotted head and a 12 fret neck.
The Australian small bodied Maton (about 00 size) has a 14 fret meck but has a deeper body than most 00 and 000s(about the same as a dreadnaught) to compensate for the smaller upper bout. It has a very strong bass for its size.
I got mine (000-S15S) at "Acoustic Roots" in Jenkintown Pa. I don't know if he has D15s. I was a little sceptical about a mahogony soundboard, but I think it is as good as spruce.
Murray