I’m planning on buying one of these this summer, and am looking for feedback from folks who have used one or the other, ideally from folks who have used both. Mission specs are to carry two folks (and eventually one adult plus one kid) and gear on mild rivers and river crossings. Very occasional useage with one paddler and a large load (e.g. a (dead) elk).
On the face of it the Duck seems like the better choice, with more elbow room for the person up front and bit less weight. Neither my wife nor I are very short, so space is a concern. The only thing which has me rethinking that is the thought that the extra bow volume of the 42 would keep the front person a bit drier, and perhaps help the boat float a bit higher and keep off the rocks.
Due to weight, cost, and manuverability concerns I see no reason to be interested in the Gnu.