I had a Midjay (the first version that came out) and it had internal styles and could read all those from the SD1, X1, etc.
It red chord changes, but not complex ones (like rootless chords or chords like min7b5, but this was a shortcoming of the SD1 as well).
I hope that the Midjay Pro can read chords the same way as the Audya does and -above all- that it has real audio drums inside (maybe not the audio guitars because I am afraid that this would rise the price too much and, moreover, nobody would buy an Audya 4 anymore). I would be happy just with the drums.