We'll listen to MP3 from an ipod or phone almost exclusively. Current system just uses a head phone jack to connect the ipod to the stereo.
It seems like that would be a weak link in the whole sound quality department.
It is a weak link but if the mp3s are of good quality it should be fine unless your an audiophile wanting pristine quality. Just stay away from Pandora or other low quality STREAMING sources. MOST people can't tell the difference between a descent MP3 from a cd anyways.
However I do prefer line in over Bluetooth though.
