This doesn't seem like a fair comparison. Of course the software's changes, bass line, variations, etc., can potentially be smoother and more realistic because BIAB can look ahead and see what the next chord is going to be. The Yamaha (and every true arranger) is REACTING to player input in real-time. Which, at least in theory, permits the player to improvise. Different tools for different purposes.

Edit: I'm more curious about BIAB's ability to convert .mp3s to MIDI. How good is it? Are they accurate??