I used to plug in my MP3 player (android cell phone) to the head unit via a 3.5mm aux jack cable. My brother who works for Apple, told me to take advantage of the Bluetooth capability, that it would sound better, it always did with his iPhone 4S and now his iPhone 5. I didn't believe that a wireless communication protocol could produce better sound output than a directly wired setup where the is almost no RF interference vs. an RF signal moving through the air.
I was wrong, connecting via Bluetooth increases the amplitude of the output signal, sounds a heck of a lot better than the 3.5mm cable setup. I can only attribute this to a couple of reasons, but as long as I know it sounds better, that's all I care. As far as radio, I don't listen to anything off the airwaves, including sat radio even though I've had cars that have come with the sat radio built in, I never liked it. I do either thumb drive music, music from my cell phone or ad free Pandora. I DETEST commercials..... YUCK.