I have got the Dragonfly today and ran some A/B testing with my Bushmaster dac. I did the test using my in-ear Sony MPA3.
Using earphones, the Bushmaster was marginally better in terms of music resolution and depth. The separation of instruments of orchestra pieces were clearer. However when playing Buddy Guy in simple music, just vocal and guitar, there wasn't much between them. The Dragonfly gives more bass so if you are into rock and like your bass with more body, then Dragonfly will suit you.
I had a look at the Meridian on the youtube video posted. Looks very promising. One thing though, if I want to carry dac around in my pocket, chances are, I won't want to carry accessories USB cables. In this instance, Dragonfly is still the dac to beat.