The thing that is tempting me to get the BK-9 is the Chord Sequencer and the key-triggered loops. For the solo performer, both of those are game changers if you want to do expressive solo work. As I've said, I won't be changing my G70 for live band use. The touch screen system makes live use FAR easier, especially for doing pickup gigs where you don't have the luxury of setting up Performances for all the songs in advance.

Plus that action is like butter!

One issue I have with most preset 'layer' sounds is that you have little (if any) control over the layer. Particularly, the velocity response. Most layered sounds suffer from the pad or string sound jumping out too much compared to the piano. If you make your own layer, you can set up the string/pad layer to be much less responsive to velocity than the piano. So the sound starts out a bit more pad heavy at low velocities, and when you pop notes out on the piano sound, the pad stays relatively the same, avoiding nasty sustaining sounds. I have rarely come across a factory preset that does this, so I need two Parts just for that trick. One more reason why three UPR Parts are a great help...