After looking around at different mufflers for the ecoboost, seems like only Flowmaster smooths out the sound. It is not raspy, and cancels the burbling noise.
http://youtube.com/watch?v=OpNXfd2u1gE
http://youtube.com/watch?v=mOKVpSqoAFU
http://youtube.com/watch?v=hWyYBAmQdWA
http://youtube.com/watch?v=OpNXfd2u1gE
http://youtube.com/watch?v=mOKVpSqoAFU
http://youtube.com/watch?v=hWyYBAmQdWA