As to your second question the XLR mic input does have a dedicated reverb effect.

The key action on the BK-9 will likely be much better than the BK-5. The BK-9 costs $1,500 more than the BK-5 and is considered a high-end arranger. I don't think Roland would risk putting in the same keybed as the BK-5. If they did so there could be a backlash from customers. People expect better quality when they purchase "high-end" products. Time will tell.

I don't see a dedicated "break" button from the pictures I've seen. There is no mention of a break button on the Roland website either. Perhaps the break is engaged when you press the variation button itself and might also be controlled with the use of a foot pedal. The BK-9 should start arriving in stores within the next 30 days. Once they arrive word will get out and hopefully all our questions will be answered.

All the best, Mike