In use, the kit is very practical, with its voice command, one press of the green button allows you to make phone calls.
Similarly, when you receive a call, just say "accept" to unhook, no need to press multiple buttons.
I use this kit with an iPhone 4S, and combining the functionality of the kit and SIRI was a fantastic tool.
He reads the SMS, and when you want to send, he will read before sending them to confirm proper redaction of the message.
No need to look up the phone to check anything, everything is controlled by voice.
Besides being able to play music from the phone by plugging it, we can also do nothing without connecting using Bluetooth, in my case it is very convenient when I put a cartoon with my son on the iPad, no connection to make, the sound is heard from the car.
In short, a good working tool in everyday life, and also very convenient for going on holiday.