amazing, isn't he? a regular walking encyclopedia

Koenig is longer, but more narrow, so rushing horizontally provides a smaller hitbox for enemies perpendicular to you. Spaekhreuzer is shorter, but fatter, so a hitbox I'd say 30-40% bigger when being targeted by enemies perpendicular to you.
Obviously, the Koenig is superior, as it has more R space, smaller hitbox, and can carry scouts, but the turning force is slower (24 as opposed to 25 on D38 and D40).