There is a difference between "Express" and "Fix + Fest". Express is practically the normal version, with which any wood can be glued, but needs some time to set. Fix is the "instant gluing". Ultimately, it's a matter of personal preference, I think. After the first planking, I coat the whole hull with a solution of the glue diluted with water, let it dry and then apply the second layer of plank. Has the physical advantage that the glue does not have to connect two different materials, but only one, namely glue on glue. Goes much faster and more accurately. But that's probably old hat.