I also have a BK9 and a BK7M, and have done a fair amount of time on a BK5 that a friend owned.

To be quite frank, I was deeply unimpressed with the BK5, I felt it’s action was cheap and plasticky, the buttons felt fairly cheap, and it’s overall sound felt a bit thinner than my personal Roland’s.

Personally, I do not think that the BK5 would make a strong master controller for a module. And it has no sliders or definable buttons, so it isn’t much use there either.

I am a little confused, though… With a BK9 being only 20 pounds weight, why would you want to use something far less capable, far less good sounding, and with a much inferior action? Yes, it is a hair longer, but still plenty compact, and the weight difference is negligible.

I use my module exclusively as a sound module for my keytar rig, and even there I badly miss the chord sequencer, VK organ section and SuperNatural guitars. I’m not seeing a compelling use for a BK5 if you already have a BK9…