I use Cubasis with Ipad 4 connected to Apogee Quartet. For midi I use the Roland UM-ONE mk2 connected to my RD700GX. In live situations I extend Quartet inputs with Behringer S16 using an ADAT connection.
6 ipads (3 are minis), 2 iodocks, 1 iu2, couple of midi interface ios and cam kit, a macbook air to deal with the midi (bidule) and to run cuemix for the m828 mk3 (audio interface) where all ins and outs are connected (no audio to/from the laptop = no extra latency).
It’s a very compact setup made to play standed, the all thing is on wheel so no problem to move it around.
A mic and a ipk mini are part of the thing, and I can conect my bass/ guitars anytime or my hardware via optical cables.
I have also an ipod that I use to control my mixes, sends, … sending/receiving osc to cuemix, and also for other midi stuff, using mainly lemur.
Nice as I have also an extra wireless headphone, so I can go for a walk on my big balcony and keep jaaamming, watching the moon and the stars 
I enjoy this setup so much that my 12 core pc with a bunch of vst and all my hardware synths, beatboxes (analog and va) havn’t seen me in a long time. Sure they are some downsides but for performing there’s nothing better, with hardware it’s to static and room becomes rapidely a problem, with software you need to set up controllers and your eyes keep going from the screen to the controllers, and switching plugi, not fun.
It’s also ecological(not that I care all that much), the all thing uses about 50 watt/h and I can turn it on and off using a single switch without loosing anything.
That sounds very cool…6 ipads? Do you have of photo of that setup somewhere?
I should glue them, my ipads are all around again, I really need more of them.
With midi clock on cubasis it was to temping to connect them to my gear, which is in 2 different rooms, then you need one to control this, one to read some pdf, one for … well you get the picture 
As soon as they’re back I’ll take a pic.
