Tell me more about this Amplifier and what phase correction is please.Really wouldn't bother. As Fox says it doesn't offer much in the way of added functionality. I think you'd have money better spent elsewhere.
E.g. if you've got HK, you could get a better amplifier and have phase correction and time alignment done.
But.. It.. looks cool! hehI don't see how anything it does is worth that - it was the first fully digital version BMW ever offered and consequently it doesn't really do much the standard partially digital one doesn't do. It was quite late to the 4 Series range, but it's the display that was originally offered on the F10 5 Series from 2012.