You're comparing apples with oranges. HAF (that terminology might be exclusive to Edward Green) soles are double sole where the middle sole is skived to nothing, once it's reached the waist, so there is only a single layer sweeping into the waist, unlike the conventional double sole where a double layer goes all the way underneath the heel. You can compare a conventional double sole to the half double sole (HAF) and prefer one or the other, but you can't compare a double sole to a single sole. Marcell's shoe has a conventional single sole. I am not comparing anything,I am just providing more explanation to what the other member said. I am aware what HAF sole is and FWIW,EG does it a lot better than Vass so there might be truth in what was said but I don't dispute any of it.