Just got my xduoo x2: with the KZ HDS1 sound is good but there's hiss, and i hate hiss.
Lucky me, i have a 75 ohms dunu impedance adapter, with it everything is blackened, the hiss disappears and the sound reveals it's true nature:
for me, it's far better than the sansa clip, soundstage is wider, no sibilance, nice bass.
This player also shows how good the KZ HDS1 really are.
Visually, the X2 is great, and the interface looks ok.
The only con is the need to use a fat sorter program to put the folders in alphabetical order: it's not a big deal, but you should not have to do it manually.
For 42 euros, it's a steal !