The TwoTrack certainly looks like a tempting product. As with all these things, how it fares in a live band situation will predominantly be down to the quality of the microphones and the sophistication of its auto-limiting facility.
The people who write advertising guff just kill me, though. In the product blurb on that Andertons page, you'll find this description of how to use it:
"Set the TwoTrack down in the corner of the room..."
Not if you're hoping for a decent sound balance and/or stereo field, mate.