I recorded the same Big Band style ending from E-A7, then BK-9 (from two high-quality demos). (Already posted in a recent thread). If the recording quality was really the same, the BK-9 sounds richer. Both demos were line-recorded.
Seems like the effects section makes all the difference here.. But where the BK-9 sounds indeed much richer, the style on the E-A7 actually is programmed a bit tricher as there is clearly a trumpet in the background thats not there on the BK9...