He uses the oscillating harrow in his direct seeding system. It helps germinate any weeds and volunteer grain in the fall. The heavy harrow has some advantages over the other harrows. It has variable tooth angle and variable down pressure, so it can harrow very aggressively. Do not aggressively harrow on low residue fields or light soil in the fall since the soil on these fields may blow all winter long if there is not adequate snow cover.
Management is the key.
The heavy harrows on the market today do a good job of what they are intended to do. There are many direct seeders who do not own a heavy harrow and have been doing a successful job of it for many years. If you have a good straw and chaff spreading system and a seeding system that gives you very little plugging problems the heavy harrow is not necessary, except for those special problems like lodged crop. Harrowing a field in the fall or early spring is one of individual requirements depending on field conditions. There is no use burning fuel, harrowing a field that does not require it.