If you want to hear your music in higher quality, get better headphones, or a better quality player - in that order. Adding a separate box, and another layer of interface that does nothing but give your ears warm (or cold) fuzzies, is just unnecessary complication. If you're really into the experience of portable audio geek, get a DAC, maybe an amp, and probably you'd not seriously look at a tiny box like the dSp. If you're not into that experience, the dSp is, and never will be on your radar.
That said, the dSp does boast some impressive spec. I just wish they'd go whole-hog and either make a DAP, or a compact accessory DAC, and not waste time on this stuff.
Thanks Mr. Pithy Shorts for spotting this.