Perfect for music transfer, speakerphone ok!

Installing goes relatively quickly, if you want to route the cables properly you need, depending on the car, of course, a little time / patience. In the event that the auxiliary port is not next to the cigarette lighter, an extension cord is.

To transfer music that thing really works well. The songs can be stopped by clicking on the button and started again and skipped with 2 clicks. So you have to just connect the phone and can start playing music about.
Interestingly, I have no cell phone noise on the connection, which are always encountered in normal connection with a jack cable directly to the AUX input, so I always had to switch to Airplane Mode.

The speakerphone works well so far, you would have to speak up, but then it's ok for short calls. Calls can be accepted by pressing a button will also find easy.
If you hold the button down, will - like the home button on the iPhone - Siri started. Here you have to speak loudly and clearly when driving, every now and then words are not understood, but it has its limits.
Of course also depends on the volume of the car / engine. On the highway it works bad, because I have so far not on the phone but only tested Siri.

What's been noticed negatively me: If you have the music / playback on mobile set very low and therefore the car radio turned up on very loud, you can hear a distinct hum. But simply I set playback on mobile to the maximum, then you hear nothing!