SPDIF in/out board for MiniDSP

MiniDSP already sells a great product called the nanoDIGI 2x8:
miniDSP Kits : nanoDIGI 2x8 K
It's all digital (inputs and outputs), has remote control capability, and has 4 stereo digital outputs (8 channels). Just add DACs. You get to choose which DACs to use, and can upgrade them anytime.

Why reinvent the wheel, AND be stuck with the crappy DACs and output network onboard the 2x4?

What is the plug-in that you claim is only available on the 2x4 platform?
 
Alas, project stalled. The ambio plug-in for the 2x4 does not support digital in/out. Bummer. Would have to do my own DSP (Probabably an ADI eval kit) but I am not sure I want to invest that much work into a system. But thinking about it.