It seems to me that the Minilogue XD is just a stripped down Prologue. The Prologue is fairly prosaic (and largely analog, since we were talking about digital) -- being largely 8 Monologues in a box. Except for one item, the programmable oscillator facility. That is definitely innovative. Extensibility is pretty interesting; of course, it's been done before (Mutable, etc.), but not on this scale.