Im late to the thread but from my readings grom audio has the abillity to use dsp and have ipod and usb drive connected at the same time. That was one thing I noticed dice media bridge didnt do. I think with dice media bridge you have to choose either IPod or usb drive not both.
I got my grom
GROM-USB2-BMW on order total is $171.00 usd shipped thats with aux and not bluetooth streaming adapter.
BMW / Mini / Rover GROM USB/iPod interface adapter
and
http://gromaudio.com/store/accessori...rsion_kit.html
GROM-U2-BMW-BMW-T (with trunk cable) - $129.99
C-35MDN (MiniDin to 3.5mm audio cable) - $9.98
C-IPD2 (iPod cord) - $20
FREE 2GB USB Flash Drive
Shipping within US $12
Total comes to $171.97
for this thread the dsp adapter add 64.99 USD I didnt order it.My X is non DSP. I may order it for future retro fit to dsp.
the trade off is that you have to select either aux input or bluetooth.. not both with grom. I guess if you already have factory aux then bluetooth will be used to add streaming.
the other tradeoff is snr ratio = 70db.. but i cant find the dice specs anywhere on the net. Next purchase is definetly the spec dock 2.5.