Jake,
I currently own an Original MoMarsh FATBOY and have hunted out of a Canyak (it was the U1 model, not sure what model your considering). Actually the guy I was hunting with was in my FATBOY and I in his Canyak. I guess just to cut to the chase, I didn't like the Canyak. We were in some pretty thin cover and the design of the Canyak didn't allow me to lay down low enough to feel hidden. The most decoys this guy ever hauled in his Canyak was about a dozen because of lack of room. I've carried 5 dozen in my FATBOY and could maybe squeeze in a few more. Lastly, the only way I would feel safe propeling a Canyak would be by paddle. Based on design of the transom or lack there of. Just my opinion. I've used a trolling motor, outboard and currently a 6.5 hp Mudbuddy on my FATBOY. And I've been told they pole great, never poled mine, too lazy I guess. Again, just my 2 cent.