I don't have any experience with the Spacewalker, but the GP 40 size Cub is great for tootling around, flies great,and the .46 is enough power to even fly it with floats. There's three or four of these in our club, and the guy who has our lake site flies his with that exact engine. I have an 80" H-9 Cub on floats, we "formation fly" a lot, looks great. His is Navy Blue, mine is yellow.