When I ordered my 2008 Expedition EL, I was told the Nav Radio was required for bluetooth connectivity (Sync?). That was the major selling point for me. Unfortunately, as discussed in other posts on this forum, I may have jumped a year too soon.

I have used a Garmin Color Streetpilot for about 8+ years and it has some features that the new nav unit does not have.

Until Sync is fully integrated into the Expedition, I would use an aftermarket gps for portability and functionality. I don't believe there was a subtantial difference in the sound quality utilizing the nav radio system.