I did a fall season Middle Fork trip (@1.69cfs) and one of the guys had a 2 person fishing cat (Bucks Bags, maybe) that had been modified to use real oars and a plywood deck in back to attach gear. I think it's capacity was 600 or 700 pounds. It was the best rig for the river, at those low flows. The 16 foot rafts were hung up all the time, and my kayak is too small to carry (enough) beer.
I've been looking for one on CL, found a couple, but the fisherfolks are (apparently) really proud of them, and want a grand or two for 'em, geez! Figured it would be great for a solo tripper boat - light enough to drag through the shallows, with enough room to bring beer.
Scadden is really pushing it though to claim that his raft is hugely popular with the recreational whitewater community!
I've never seen one of his rafts or fishing cats around here, but I'd like to run one of those little 9 foot fishing cats down the Main Payette just for shits and giggles as long as I wasn't responsible for any breakage!