Spotted another issue over this weekend whilst doing a two day music festival, which was multi-gesture induced lag. Basically, where I was running two channels that were related and I was using two fingers to move their respective faders they would become very laggy and then continue moving (ghosting) after I had taken my fingers off, making smooth fading and level setting difficult.
This happened across all the iPads I was using on the system at the time, one docked, two on wireless.
Once I have unloaded all my gear I'll get a video.