An act of genius this boat is.
My earlier stints in the boat had either not fully inflated or not included all the pieces. That was clearly a mistake. The back rest makes me sit up straighter than my mother ever could. The foot bed offers a secure and familiar but much, much improved pushing platform common to non-thigh strap packrafts. And the X-ray, while a bit scary in concept and images, clearly adds benefits I have not seen with thigh straps, namely the "knee-cup" effect that so many kayakers would like in a packraft. I was able to role over and over and over and over (sweep rolls not C to C) in the icy cold river today and surfed more waves and play-holes than ever before. It's a joy to paddle.
The boat is faster forward than a conventional Alpacka but just as nimble. While tippier, the added control afforded by the X-Ray more than compensates for the tip and gives an incredible oneness/snugness with the craft. In fact it's neat to work on bracing out on the edge and sculling to keep it.
The boat was so much fun that I couldn't bring myself to accompany Brad back to the car below Campground Rapid and joined a trio of passing packrafters for an extended float down to the play hole on Base and beyond.
Thanks Alpacka for another great idea: a class V packraft. Now I just have to become a class V boater.