I use them but only occasionally--If I've got too many archers to spread out to just two or three deep and still keep a concentrated front I'll put them in a double line, and if for example I've got infantry and light cavalry working together to guard a flank I'll set them to 3-row infantry first so the horses are protected till it's time for them to do their thing. The column can speed up bridge crossings a bit (and possibly massed entry through a castle gate?) but I can't think of any other practical uses for it. I don't have much use for most of the others in my tactics.