Thanks guys, yes the focal plane shutter in the Mamiya vs. the leaf shutter lenses in the blad, that's a huge difference. Any more thoughts on this?

Bill, I too like square better, but some things work well in the rectangle. The nice thing is that 6x6 offers the ability to do both which is a huge advantage, and also not have to flip the camera on a tripod. Another advantage is that I have two backs already for my SWC, which I could switch back and forth from the two blads.