Just thought I’d let you know I’ve tested a Propellerheads Balance and Novation X Station with Cubasis running on an Ipad Air and using a powered usb hub. Both seem to work well for audio recording and playback with Cubasis. Shame you need a powered hub but still very useful for making location recordings or writing using the silent ipad. The X Station can also of course be used as a midi controller to play the Cubasis instruments and hopefuly the planner automation updates should help with midi mapping and transport soon.
Rob