I really liked the sound.  I'd been using my Galaxy S4 for mobile listening and adding this DAC/amp made a definite improvement in sound quality.  Detail improved, most noticeably in the lower bass region and the sound stage got a tad wider.  The battery life was great and I liked being able to charge my phone from it.  I thought using the bands to strap it to my cell phone might turn into a PITA, but I found it was reality easy to deal with - YMMV.  Overall, I was pretty happy, except if I moved around my pants pocket would rub up against the volume knob and change the volume and that just gets on your nerves after a while, so I'm returning it. 
 
That said, I was impressed enough with the product that I'll probably exchange it for the e17.    

I have the Bass Edition.  They're good earphones.  I found the sound quality a little lacking in detail in the upper mid/treble range.  I'm not sure what that was about, since I eq'd them to near flat response - they just never sounded right with rock and heavy metal.  My Shure e2c's are much more detailed.  They did have nice extension all way from sub bass into the ~10khz range with a little help from the eq on the top end.  Overall, they do sound good (when sealed).  I like them better than the Sennheiser Momentums (in-ear) and the RHA MA750 as far as sound goes; the GR07 is more neutral and detailed than either then Senn's or the RHAs.  I'm not sure why these are marketed as the "Bass Edition;" the bass is pretty neutral/flat.     
 
I was never able to get a good fit/seal.  I even tried the meeaudio m6 triple flanges, but they went just a tad too deep into my ear canal and the included bi-flanges wouldn't remain sealed.  Something about the square housing and the nozzle prevented me from ever getting a comfortable fit.  Maybe it's just my ears; clearly others are having better luck.  OTOH, this is the first IEM that I found uncomfortable.  I do like the included earhooks and found a similar product on amazon for use with my other earphones. 
 
I do have to ding these pretty good in the value department.  You can get two pairs of the NVX EX10S for $70 or $65 for a single pair from sonicelectronix.com, and those are very close in performance to the GR07.  The NVX are probably made by vsonic for NVX or in the same plant that makes the gr07; I know NVX has used other companies to make their equipment on the car audio side.  That means you're paying anywhere from 2x to 4x the cost for the vsonic for a similar product.  The RHA MA750, which is in the same price range (but different sound signature), has far superior build quality.  The ~$100-$150 category is really competitive with some balanced armature IEMs getting into that price range, the Shure se215 has a detachable cable, many competitors offer a mic/remote in that price range, etc, etc, etc.   

Build quality is great and they're so much more comfortable than my GR07s.  I really wanted to like them, but I just couldn't get them dialed in.  Even heavily EQing the bass and treble down, the mids still sounded recessed and lacked detail.  The thumpy bass is nice, but the novelty wore off quickly.  I work in the audio industry and I understand a lot of people like a "hot" top end with a fat bottom end - if that's you, then these would be a great headphone for you.  If you're looking for flat response, with detailed mids, then I have to say give something else a try.  I think these would also benefit greatly from an amp if you're considering these for use with a phone or tablet. 
 
Based on build quality and comfort, if RHA ever comes out with IEM with flat response, it would be high on my list to try.