Hi:
I understand your topic very well, myself as a former organist I am use to play several keyboards, when I change into the arranger keyboards, I like to perform with 2 arrangers, I use my T2 and my Korg PA60, that I just sold to a colleage here in Phoenix, for now I am playing only one keyboard and I find myself a little short in resourses, simply, by changing my right hand I have another sound and so on, and now I will be waiting for the release of the PA800.
Here in this link a picture
http://members.cox.net/arizonaballroom/Manuel.html Using 2 keyboards is more to carry and more conections, but to me, is worth the effort, I enjoy having a great pallete of styles, sounds, functions, etc...and as everybody knows, every brand has it's strengths and weakness, this way I kind of cover what styles are better for one thing than the other and viceversa.