I bought the SD10 and SD50 to choose one that suits me best (and repack the other). The 2 have a sound quite correct and mate perfectly with my ZTE Blade S The scope is correct for Bluetooth, you can move around the room, but do not expect to trudge throughout the house. The SD10 is probably a little less bass, the scope may be somewhat smaller (not very clear), announced autonomy is better (20 hours), it is lighter and more importantly, it holds better on the head. So I chose the SD10 for his good behavior that allows better to be active while listening to what we want. The ideal would have been the quality of the SD50 with the shape and weight of the SD10 ;-)
OGADGETHUB purchased from 20 in January 2013, delivered by AMAZON.