streamin,
I would say that by using the moldboard plow first - it sped things up somewhat. If I used the disk harrow only - I would have to make additional passes to achieve the same results.
I actually have used the disk harrow only, on a smaller plot. That's what led me to "make" a 400# square of concrete with a lifting handle, top dead center.
The disk harrow is light weight - Land Pride DH1048, 412#. The "square" of concrete doubles its weight and GREATLY improves its digging/cutting abilities.
I just lift the concrete and set it on the disk harrow before I hook up. I was going to upgrade to a unit from Brown mfg or the like until I saw the price and shipping costs. This alternate is not as good but for my limited uses it works just fine.