I had previously owned the Roland BK-7M and really liked the sound it produced. I thought the BK-9 would be the same but it just wasn't. Here is a song I recorded using the BK-7M. I was never able to get the BK-9 to sound the same.
By the way, I sold the BK-7M only because, not being a midi guru, I didn't know how to setup a controller to do all the work from the keyboard.

Deane