Out of curiosity I was wondering why more people don't use the Roland BK-7m and a 61 key controller keyboard combination? Much has been written about how great the BK-7m is and one can pick up a 61 key controller keyboard with semi-weighted keys and aftertouch for $400 or less (e.g. Akai MPK261). Add in a small keyboard amp and the price is about the same as a MOTL keyboard (e.g. Korg Pa900).

What are the pros and cons of going this route? (Other than not having a voice processor.)