I have it.
I have an iphone and it connects automatically and starts playing the last music program i had open on my phone when i hop into the car(via bluetooth).
As for the going though folders and what not, you have to use the buttons on the HU. You can only scroll and pick your song on the wheel controls.
If I plug the connector in, it auto plays Itunes. If you want to use another program, you have to start it up on your phone. I use pandora and di.fm, and neither of the will show txt of the song on the sonic's HU. The HU will show the itunes paused song.
The audio sounds better through the connector vs bluetooth. I believe the connector has more bandwidth than the bluetooth. If you dont understand what bandwidth is, the thing youll notice is that some of the bass gets cut out when using the bluetooth vs the connector.
Another unrelated issue is that the max volume on the stock system is not loud enough. Its an econo-box so its understandable that they put a 40x4 W max stereo system(im guessing thats what it is, but i wouldnt say its anymore than that). Sometime early next year Ill be going balls out on a system (pics to come).