I had the iphone 4S with IOS 6 and was blown away with the performance. I upgraded to the iphone5 and that's when it went downhill. I upgraded the firmware to make it functional for the most part in all areas except for listing to audio. There is a 1-2 second delay in the audio the device which wasn't there in the iphone 4S. I also notice that if I also have it paired with another device like my ipad or my PC the audio quality with my phone gets very choppy and unusable. So iphone5 users beware.