@Feg, nice write-up. I knew that MMX 300 was based on the DT770 LE and tuned for gaming - it's good to hear some praise of it's qualities. Beyer's PR guys really didn't get the message out that it was most certainly not just a plain old 770 with a microphone; as that's all I heard from the forums etc when I was researching this headset.
Did you get a chance to check out the microphone's quality, or the what was the owners thoughts on it? I think this new version was meant to be improved over the older model. Was it the 32 Ohm or 600 version?
Shame MLE didn't get a chance to review it.