I would also read through the threads on rolandarranger.com. Especially Diki writes a lot of true things there, for example that the conventional saxophones (that are in the BK-7m as well) sound better than the SuperNatural one.
He also stresses the importance of the chord sequencer, which I strongly support; it is a main reason why I think I'll keep the BK-9. It opens many possibilities for your left hand.