I got my Alpacka back last week complete with the new whitewater deck. There hasn't been much chatter about this, my guess is not many people have it yet.
I have yet to try it out on the water; however, my initial impression is this deck is a total game changer in packraft design. I look forward to being able to run the water I enjoy without stopping to dump. The cockpit size appears to be close to a medium (#4?). It would be really sweet if some kayak spray skirts fit. I don't have one laying around to try. I imagine I would use the beefier neoprene skirts for roadside runs and save the Alpacka skirt for backcountry adventures.
Here are a few shots of the design taken with a crappy IPhone camera:
The first picture shows the pieces that make up the cockpit rim, two curved aluminum tent poles for the sides, and two PVC dowels for the bow and stern. The PVC slips in each end and the sides zipper.
Here are the two pieces fit together:
One side zipped:
Both sides zipped and spray skirt on: