I recently came across a second Polaris on the cheap (lucked out big time!) and I'm considering linking the two units together.

Is there an advantage to using the Chroma Interface over MIDI? As far as I could tell from the Interface manual it doesn't seem to offer any more functionality other than the Interface being parallel versus MIDI's serial buss.

Did the aborted Polaris Expander have any other features (eg. increased polyphony) over linking two Polaris keyboards together?