Red leaf is more expensive and has little fleck/worm track in it. Red Leaf Soft Maple in the better grades is substituted for hard maple, particularly for furniture.
Soft Maple, Red Leaf
Soft Maple has the same general characteristics as Hard Maple, but nearly as hard or strong. Red Leaf Soft Maple is close grained and resembles sugar maple, but is softer in texture, not as heavy, lacks the figure, and has somewhat poorer machining qualities.