But sound quality is top, not screened properly.

Unfortunately I have despite the good sound quality Cons distribute, because the cable is not shielded properly.
So if you want multiple people to make a film or something in general, you have to ask everyone to put his phone on Airplane mode, otherwise the radio waves interfere with almost permanent.

Edit (17/02/2015)
I must apologize for some criticism. I have now made a complete movie in Taiwan, and despite the fact that everyone was wearing his phone there were no problems. I live (only during the summer) to be turned on during the film shooting with relatively poor up veeeery bad radio reception, and there it was absolutely impossible for the cell phone's in Germany on a village.