Its crap
I have just returned my Soul as have 2 of my friends. Asthetically its brilliant and it overcomes all the issues with the interface on the D900 -BUT you cannot hear the person on the other end in a phone conversation. It appears that the phone does not have the performance needed to process sound, in other words its crap as a phone. Sound keeps dropping out and its not a one off, my friends and I have them from different batches and even different providers. It even does it when trying to listen to voice mail.
DO NOT get one of these until it works as a phone