Oh dear - I was the one who knew all about digital mics. when I worked as Technical Manager at Sennheiser UK, but I left there about 6 years ago.
I have written a couple of AES papers on AES42 digital mics and do have a DMI-2 and two DMI-2p myself, as well as both Neumann and Sennheiser digital mics (and an AETA 4MinX which will also accept AES42) - I also plan on giving the Gefell one a test when I can.
I have attached my two AES papers should anyone be interested and I also have PDFs of a few magazine articles on AES42 microphones on file.
I'm happy to help with AES42 questions if I can.
AES 130 - Digital Microphones - What's it all about - John WIllett.pdf
AES - Digital Microphones - AES42 and all that.pdf