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.)

I used a setup like that and BYW have it for sale. Check the For sale forum.

Pros-Very light and compact, easy to use and sounds great. Inexpensive
Con- more cables than a single board.

I fell into a great BK9 deal so thats why I don't use the setup

I used that setup for quite a while and it worked very well. I was having to use a lot of peripheral gear with it though.
Needed an external screen if you want to see midi lyrics, a laptop for text files, a mixer for vocals, an external vocal harmonizer, an external recorder, and all the power supplies cords, midi cables, etc to use all this.
A lot, but not all, could be left connected if you have a setup that allows it.
I found I prefer an all in one keyboard.

I just purchased a BK7m for the same purpose, but I want to pair mine with a Hammond XK-1. I agree with Don about one keyboard, but this is a special situation for me. I'm glad to read that others have had good experiences with the 7 and another keyboard.

Once you list all the peripherals requiring setup and tear down an all-in-one does seem much more appealing. (And the Korg Pa900 does have semi-weighted and aftertouch keys.)

I'm quite happy with the PA900.

Apart from using the BK-7m selection wheel (I think it contributed a little to my chronic tenosynovitis near the ellbow), I think it is an extremely practical and good sounding module (except acoustic guitars and certain strings).
Here's a new recording of BK-7m with MoXF: "Killing me softly". Only the strings (coming in later) are from the MoXF, everything else from the BK-7m. It is played with a style, no midi file. With the MoXF and BK-7m together, you have a great choice of sounds, and the MoXF6 is very lightweight.

http://youtu.be/_qoezMe_6wM

BK7M does have some very nice styles....well done

Thanx

The biggest gripe with modules like BK7m is the placing of the buttons, they are smaller and in most setups further away from the keys...

I think its better to use a keyed arranger as the base of your setup, and then add a soundmodule to that..

If you are able to place it like in my video (it is on the edge of the MoXF, supported by the back part of the keyboard stand with a supporting specially cut styrofoam block underneath), you can reach the imporant live buttons for arranger functions easily enough, and the buttons are fairly big. Changing individual sounds however is difficult, you have to prepare sounds/sound changes at home, e.g. by preparing performance lists for the USB stick.