So, I've had a bit more of a play with it and my impression is that the effects are pretty good for accentuating parts of a song (eg. a solo with a spot of chorus) and the tracking for the octave effects is spot-on.
However, the overall sound with no effects on loses something; I'm connecting it via a GigRig Quartermaster looper switch and switching it in is noticeable.
Based on that, I wouldn't use it as a single fly-rig preamp unit.
I also made a separate two-switch box and configured that; I spent a while wondering why only switch FS5 would work, but then I found that I'd set the option to say FS4 is patch up, but I also had to set another option to configure it as a switch rather than an expression pedal.