The phone book access function actually highlights the hands-free calling function of the Bluetooth by displaying the name of the caller, of course when you want to call someone, no need to find the name from your screen-limited smartphone, the head unit will do the same work.
I found the most useful function of MirrorLink is to mirror the Google map to the infotainment screen, which gives me a wider and clearer view of the map, the guidance voice is louder, and it saves me an extra cradle. (Be aware that MirrorLink function works for the Android phone mostly, if you want to use it to link to your iPhone, an extra CarPlay Dongle will be a smart choice, I will explain it more next time.)
If you have the same bad habit like mine, hate to hear the same song or get sick of some songs for a while, the steering wheel control function will save your day as well. Control to move on to the next song is only one finger away, if you want to sing with the song, the volume control is still just at your hand.
Next time, I was thinking to talk about the car stereo functions that require extra devices.