I was raving about the specs of this looper during our looper discussions here a while back. I thought it'd be the looper's holy grail. Til I found in deep in a review somewhere that there is not an easy "Undo" button. You have to record a complete loop on the duff track with the volume down on that track. For long loops of a couple of minutes that could be a pain, quite apart from having to fiddle with the volume knob.
Given the theremin is prone to the odd "false start" pitchwise - in my hands anyway - I don't think I could work like this.
It also from reviews seems to be a bit delicate - especially if you're used to the Boss.
http://reviews.harmony-central.com/reviews/Effects/product/Electro-Harmonix/2880/10/1
PLus depite what GAK say - I think it's a 4 track not 6.
There's lots of interesting things about this pedal though - separate track volume sliders, bouncin down, saving to flash car (tho only one loop per card) etc. Ilm sure one could do some interesting things with it if you could work around the undo operation.