I was surprised to read a bad review in what hifi magazine but the reviewer must have a poor sound system because to my ears and my father who is also an audiophile this has a much more refined sound than the audioquest dragonfly, I can hear so much detail and the vocal midrange is way better as well as the sound stage. The only thing I can critisize is that it heats up quite a bit.
GrimurI use a variety of different headphones but they all sound better plugged into the Audioengine D3. The ones I use most are Blue Lola, AKG NC60, Atomic Floyd in-ear headphones and Monster DNA.