Pros: compact size; cool, simple look; good intonation; good quality construction
Cons: lack or warmth; lack of sustain
Readers of my guitar reviews know that I like Martin's 15-series guitars. They are all solid wood mahogany guitars that are cost-effective and fun to play. The sound is generally good, warm and inviting, and I think you can have any of them for under $1000.
The Martin 5-15 is a TINY little guitar. I tried to research its lineage, but I couldn't find anything on Google. My hunch is that its modeled after some very small guitars that were around in the late 1800s, before the big old dreadnought (for which Martin Guitars became famous) was even a twinkle in some guitarist's eye.
The 5-15 is even smaller than the Little Martin or Larrivee's parlor guitars. Its shape is reminiscent of Martin's larger 12-fret models, and indeed the 5-15 has only 12 frets clear of the body. Scale length is a very short 21.4" (your average dreadnought or OM has a scale length of about about 25.4"), and the body itself is much shorter in both length and width than anything else I'd played recently.
The back, sides and top are made of mahogany, or so I thought until I visited Martin's website. Apparently, some of these guitars are made of solid sapele, a hardwood with characteristics similar to mahogany. Neck width is 1 11/16" at the nut, which is the norm for most guitars.
Ornamentation is minimal, as it is with all 15-series guitars. There is no purfling or binding to speak of, and the rosette is a simple black and gold Herringbone decal, as on other 15-series guitars.
So how did this little guitar play and sound?
I prefer smaller guitars, and this guitar felt pretty comfortable in my lap, though it was almost TOO small! Intonation was good and chords up the neck the guitar were in tune. Overall playability was good, as was quality of construction. The rosewood fingerboard had just the right about of resistance. Because of the short scale length, string bends were easy to do.
But I can't say the sound really satisfied me. From the first strum, it sounded a bit thin and jingly. There was no real bass to speak of, and sustain was OK but nothing special. The guitar was punchy in the upper midrange, but probably too quiet for playing with others (forget about using it for bluegrass). And it wasn't sweet and liquid enough for fingerpicking either.
After a few minutes of playing, I started to grow used to the sound, and the word "distinctive" started going through my head. I'm not sure if it's fair to compare this guitar with larger guitars. For some blues tunes, it sounded kind of cool. The guitar's woody undertone and punchy midrange made it suitable for some retro sounding acoustic blues tunes. But even there, the lack of lower midrange warmth, and the lack of any bass to speak of, sometimes made me feel like my mojo done gone and my heartbreak don' matter no mo'.
When I returned to the guitar store a few days later with a guitarist buddy, we compared this guitar against the less expensive Little Martin, a laminate guitar that is a great deal in the $275 price range. As I played, I found myself liking the 5-15 more than I had the first time I'd played it, but I still wasn't convinced it was worth $700. The overall volume level was actually pretty good (though not comparable to that of larger guitars), and the intonation was impressive. The guitar sounded in tune. But my friend (he was listening as I played) matter-of-factly said he preferred the sound of the less expensive Little Martin. We moved on to other things.
To conclude, if I were looking for a small guitar, or a starter guitar for my youngster, I'd probably go with the Little Martin in one of its various incarnations, or perhaps the Taylor Big Baby. Both can be had for less than $400, and both sound better to me (and my buddy) than this guitar. My hunch is that this is a sort of "specialty" guitar, aimed at duplicating the specs of some very early Martin guitars. It succeeds in that it's well-made, looks kind of cool, is VERY compact, and has good intonation and a very distinctive sound, but it ultimately failed to satisfy my modern ears.
If you like the all-mahogany look, and want one one of Martin's 15-series guitars, I really like their 00-15, 000-15, and 000-15S (short scale). The D-15 is a nice dreadnought as well.
And if you don't mind laminate guitars, the Martin D-X1 and 000-X1 are wonderful bargains in the $500 price range.
In its defense, the Martin 5-15 may sound something like the smallest guitars Martin made around 1900. I think I played one of those guitars many years ago and came away with a similar impression. But as a day-to-day playing guitar, the Martin 5-15 didn't quite do it for me.