Our local music store got one in today and I happened to be there.
I had to show them how to work it!
I like the ability to address the module with an external keyboard controller. There are many things you can do that way that you can't do, or that are harder to do, on the BK5.
For example, I have direct control (one-button) for all intros, endings and break/fill. On the BK5 you have to push two buttons to select the ending or intro you want, and there is no button for the break.
I can also address sounds, variations, performances, fills, OTS, and countless other features all with single assigned buttons.
Between 50 programmable buttons or sliders, the 5-button foot switch, sustain pedal on the controller and assignable pedals on the module, I have more than enough controls.
Also, there didn't seem to be as many styles on the keyboard, but that could be a misconception.
The keys felt really flimsy after playing the Korg PA3X, and they are really short too.
Speakers sounded o.k., but certainly not loud enough for anything outside the home.
The Sound Bank buttons double as OTS buttons. Not sure I like that either, but didn't play it long enough to form much of an opinion.
I only played with it for maybe 15 minutes, so not certain my opinion is worth that much.
DonM