[ruined]

I have the sony MEX-BT5000 and I would say avoid it. A2DP works great with AVRP, quality of call sounds great through the speakers, but the placement of the mic in the headunit is unfortunate. Everyone I talk to says i sound distant and muddled. Honestly, it's bad enough I have stopped using as a handsfree device. I know you are looking at the 5100 but the reviews I have read say it has the same problems. Two other annoyances are: it will not display rds and HD information (from the external HD tuner accessory) and more annoyingly, the curved highly reflective faceplate pics up so much glare it is almost impossible to use in daylight.