I've had the Microtrack running almost 5 hours now with a 4 AA battery USB power supply (using 2500 mAh Lenmar batteries). When I unplug the USB power, the battery indicator is down to 1/4, but the green light on the USB box is still on. I'm doing all line-in (no phantom power, no monitoring).
Issues with SPDIF in. When I selected SPDIF on the MT menu, it set the sampling rate to "automatic" but the bid depth changes to 16 and I can't access the change menu (though it works for analog-in selection of bit depth). ANd feeding the MT with the output of my Grace V3 (via the RCA out) just got the MT to lock up. Another call to tech support, this is a known issue, probably the one we were hearing about a few weeks back from the guy in Spain. It will be fixed in the famous firmware update WHICH IS EXPECTED IN A WEEK OR SO. I'm not sure how good this estimate is, since US tech support doesn't have access to MT 24/96s yet.
Jeff