The Martin D-17
In the early 2000's C.F. Martin & Company for a while manufactured the Martin D-17, a guitar that combined the building specifications of the Martin D-15, and the Martin D-16's. First and foremost, and visually obvious, is that the Martin D-17 is an all mahogany guitar just as were the no longer produced "17 series" instruments of old, and as the current "15" series instruments of now. The use of a mahogany sound board or top on this instrument creates a very very different tonality from the more common spruce soundboards that not just Martin, but nearly every steel string dreadnought manufacturer uses for the largest majority of their instruments.
Mahogany top guitars are not uncommon, and they aren't even slightly new ideas, and of course they are not bad ideas either. They just produce a much more cold, stiff, and darker tonality than do guitars with either spruce or cedar tops. Spruce and cedar are conifer woods, mahogany is a hardwood, and so the mahogany soundboard will not vibrate so thoroughly or freely and will not produce the volume that either spruce or cedar tops can and do.
Regarding the lesser volume of mahogany topped acoustic guitars, don't overly fret yourself about it, just fret the guitar - all Martin instruments are available outfitted with pre-amp and pickup electronics for amplification.
Pretty obviously, an all mahogany guitar will look quite a lot different from the conifer topped guitar too, and isn't the mahogany top instrument also very beautiful? I say it is, it just won't sound like what you are used to, but boy does it still sound wonderful!
The Beautiful Martin D-17
The Martin D-17 Acoustic Guitar - All Mahogany Top, Back, and Sides.
So Just What Is A Martin D-17?
The Martin D-17 was run for a limited time in early 2000's. This was a unique high end version of the inexpensive D-15 and 16 series, but with quality solid Mahogany front, back and sides; a solid one piece Mortise/Tennon neck joint, genuine Mahogany neck, Style 17 Rosette, D1 Hybrid bracing 1 Style scalloped, Style 18 purfling, Tortoise color binding, modified low oval neck shape, White Corian nut, black Micarta fingerboard and bridge with a Polished Gloss finish on top back and sides.
I've seen it stated that the D-17 is only a D-15 but with a gloss top, this is entirely untrue, the specs I've provided above suss out some more of the differences, and regarding the micarta fingerboard or fretboard, Micarta is not a bad thing for fretboards, I think it's a good idea, it'll outlast wood, some may argue that it does effect tone, but this is a matter of some debate. In any case, the use of micarta is becoming more frequent, and can be applauded in that it is just one more way to aide in the manufacturer and consumer's responsibility to end deforestation and consumer responsibility to the environment we all share here on planet Earth.
Micarta is inferior to tusq or bone for nuts or saddles though. If your D-17 has a micarta saddle you can get a bone or tusq compensated saddle, or not from a Martin dealer.
The D1 hybrid bracing is not something found on the D-15 at all, and neither is the Mortise/Tennon neck joint, and of course the style "17" rosette is another cosmetic thing not seen on the less expensive D-15.
Do you want to know what is great about both the Martin D-15 and the Martin D-17?
I'll tell you right here and right now what is great about the all mahogany top, back, and side Martin guitars, they look different, they sound different, and ....they are way LESS EXPENSIVE than any solid wood Martin with a spruce top, and why is that? It's because spruce is expensive, that'd why.
There is no sort of anything to back up any person's claim that a spruce topped guitar is "better," it isn't. There is nothing "better" about a guitar with a spruce top, unless, of course, you application for the music you intend to make with said spruce top guitar includes the tonality associated with such instruments.
Give yourself space, you may be a totally unique musician and your music might require a different sort of tonality from your guitar. Listen, everyone else is playing a spruce topped guitar, be it a Martin, a Gibson, a Taylor, a Breedlove, a Takamine, a Yamaha, or any of the other thousand and one brand guitars out there.