As great as this sounds on an iPad (using Focusrite iTrack Dock), without useful patch call-up and tap tempo, it's pretty well a one trick pony. Yes you can switch effects in and out, and I suppose if you had a large pedalboard that might give you enough variation for a set. But I have an FBV Express II, so 4 pedals, can't do a lot with that. And tap tempo is an absolute must for me.
Other quirks: The tuner can't be brought to full screen without using your fingers, so no good on stage. Means I'd have to take a physical pedal, or use one on the iPad and not see the Rig.
Cannot open the edit screen for each effect just by tapping on it, and when you open it with "show" you have to close it with the little x on the effect. I know on stage this isn't vital, but it makes adjustments tedious even when setting it up at home.
It's already been mentioned somewhere about the long list of effects brought into view when you try to insert one - far better to have them in folders by type. Having to scroll through every effect is a pain.
This could really give BIAS FX2 a run for its money. I love the sound of these plugins, really natural and great on a live electro-acoustic guitar (though there's some intermittent noise coming from the analogue chorus pedal). The ability to have the sound directed to just one mono output is actually incredibly useful (and BIAS cannot do that) because I'm trying to build a live rig with a vocal chain separately processed, and that needs to go through an independent output. So I can feed the sound person a mic and a guitar channel. Never easy doing your own vocal/guitar balance from the stage.
All in all this shows real promise, but looking a t the timeline of updates I'm not holding my breath for serious development here. May have to use just the plugins in Audiobus, but I'd still miss tap tempo, which I think just about every other app of this type supports. Hey devs, wanna give us some hope? How much do I need to invest in your company for this to get some attention - 10K, 20K....?