I will probably be getting rid of my E46 before long but I have enjoyed my Dynavin V5. I use the USB function everyday and have liked the bluetooth capabilities. However, the one thing that continues to drive me crazy is that my bluetooth phone volume is almost intolerably low - I have the bluetooth phone volume turned up to 39 and can't hear callers that well in the city, and can barely hear them at all on the highway. Bluetooth music is much better. I'm thinking maybe my phone (Droid X) is limiting the volume because it recognizes the Dynavin as a bluetooth headset instead of a car kit. Oh well.
Edit: forgot to add that I am on the stock, non-HK amp. Volume is pretty low overall but I have considered trying the Dynavin's internal amp with 4 ohm 6.5" speakers to see if it helps.