Does anyone here use the Alpine Flex Plow Extensions???

I’m just curious how well they work…and whether or not the "boxed in" edges of the plow keep the snow from rolling off to the side when plowing large open areas??? I was also wondering if they get caked up with snow when the snow is heavy or wet??? I wouldn’t mind having a wider plow but I’m not sure about the "boxed in" edges.?.? Are they worth buying/adding to my plow or should I just stick to the straight/standard plow blade? Thanks!