I would rate it handy in a worst case scenario, and just about "practical end game" quality in other scenarios. I own and use both the 1.0 and 1.2 on a daily basis. I find the 1.2 to work as advertised, meaning a slightly smoother sound. I find 1.2 to be superior to 1.0, but only slightly and only enough to be in any way significant with certain headphone pairings and not with all. For my HD-700, 1.2 is the clear way to go, for my other headphones past and present, probably not enough difference for me to care 98% of the time.
Regarding 1.0 to 1.2 comparisons, my take on this is that regardless of which one is preferred, others have noticed differences between different units that are just as significant as the differences between versions, so my take away is that this is all a very delicate balance of manufacturing run, condition, USB power supply, headphone pairing, etc... In my limited experience, I would simply describe the Dragonfly 1.0/1.2 collectively as a 7 to 7.5 in the world of DACs, with 5.0 being the internal DAC of a MacBook pro or iDevice and 9.0 and higher being the best stuff you have ever heard and your BS descriptions and rankings all fall apart the moment you are blindfolded. And anything 8.0 to 9.0 is stuff you can clearly and consistently hear as superior to most other stuff. Based on a lot of reading and just a little bit of experience for example, I would rate the Schiit Bifrost an 8.0 and the Bifrost Uber an 8.5.
Regarding pairings in general with the Dragonfly, either version, here is my experience:
Note, I don't do IEMs at all, so just on ear or over ear headphones... in my ranking system, a 5.0 is generally adequate and a 9.0 is so superior that it is hard to imagine the headphones scale up anymore even with a better DAC/AMP combo in the chain. For me, a 7.0 or better is worth paying attention to because getting better results often involves something closer to a thousand or more worth of gear than just a couple hundred to maybe five hundred dollars worth of gear (the electronics stuff, not counting the headphones...) So the numbers are relative to what I think the headphones are capable of, not a reference to absolute sound quality.
AKG K550: 8.0 Really good synergy on bass and mids, but there is an etch or sharpness to the highs on these phones that never sat right with me, and the Dragonfly didn't do anything to help tame them. So not the Dragonfly's fault, I just think these need something warmer.
AKG Q701: 6.5 Not quite enough juice to bring the goods and still a bit bright since these are slightly bright sounding to begin with. A welcome improvement over direct to MacBook, so a reasonable temporary system for the Q701 lover but upgrades ASAP are still in order. Just not enough juice to show you what the Q701 is capable of
ATH-ESW9: 8.5 I love these headphones, and the Dragonfly helps brings the highs out a little better without doing any damage to the slightly syrupy midrange, which is balanced nicely with some decent bass... these are great headphones that should be more appreciated here on head-fi. If there is ever an argument for coloration being a good thing, these headphones make the case. So better DAC and amp may do a little more justice to full spectrum, but the Dragonfly is an awesome pairing with these, bringing a little extra tightness and punch to the bass, some better instrument separation in the mids, and a much needed dash of sparkle to the highs. These headphones work better than anything else I have ever tried directly into iPhone or laptop, but the Dragonfly is such a perfect partner, I have to have it in the mix from now on...
Bose AE2: 9.0 these aren't bad headphones, but they are wasted on anything better than a Dragonfly IMHO, otherwise a bit dull sounding but the Dragonfly helps juice them up a bit... and the extra treble definition that the Dragonfly can provide are most welcome here. Bass tightens up a bit too since I normally find them a bit wooly/muddy when I am direct to iPhone or MacBook.
Senn HD 555: 8.0 good clarity and plenty of power since these are fairly easy to drive, but nothing special, still sound like Classic Sennheisers (and I think that is a good thing in general), but at least you get the sense that there is a bit more solid foundation underneath it all and they won't run out of power like they did on my other laptops all the time.
Senn HD 700: 7.5 a little bright on occasion, but plenty of drive and solid bass with clean mids make you very happy if you like HD-700 signature in general. Much better sense of speed and control compared to direct consumer sources. I am anxious to upgrade to a really nice DAC and amp to do justice to the HD-700, but the Dragonfly sounds so decent that I can't justify jumping through any hoops to do so quickly..all in good time, and the Dragonfly need make no apologies while it continues to serve as my interim source for serious listening on my best headphones. At a recent meet I went from Dragonfly to Bifrost / Bottlehead Crack with same headphones and same source (Mac Book with JRiver MC). Definitely a solid step up, better bass and a more organic sound, smoother highs and a better sense of depth and layers. I would rate that combo a 8.5 or maybe even a 9.0 with the HD-700, but again, when I went back to the Dragonfly I didn't feel desperate for something better, just looking forward to what I know is the next step up at some point down the road.
Hope this helps anyone still on the fence about the Dragonfly vs going with a more substantial desktop system.
