I don't think P28 is shorter in blade length, I just think the actual curve is a little more pronounced (deeper maybe?) so it tricks your eye into thinking it's shorter. It's like, which is shorter, a straight line that's 4 inches long, or a segment of a circle that's 4 inches from start to finish? Both are 4 inches long, but the curled line of the circle would probably fool your brain into looking shorter because it takes up less room in a given area.