Roundup Weed and Grass Killer Super Concentrate, 1/2 Gal

In the past I've only used the Extended Control Roundup concentrate, but bought this Super Concentrate Weed and Grass Killer this time to save some money, see how it would perform, and to be able to re-plant in the sprayed area sooner, if that's what we chose to do. We sprayed it in 2 different areas - one that was bulldozed about a year ago into a steep slope and now had tons of dandelions and some other taller weeds growing there and the other was an undisturbed flat area of mostly grass and some dandelions and lower weeds. Both were sprayed (saturated) with the 2.5 concentrate dilution in a pump tank sprayer, and took nearly a week for most everything to turn brown, but there were still a few listed weeds that never died. On the flat area, we then had a 4-5" layer of topsoil dumped and spread on top of the dead stuff. Weeks later that became covered with various types of weeds and growth, so we first weed whacked, then mowed and raked the area, then sprayed it with an even stronger dilution this time. That was now a week ago and it has a spotty brown dead and green still alive appearance. It looks like it would take another application to fully kill off everything. All spraying was done in sunny weather with no rain for at least 1-2 days afterwards, which should have been ideal, as it says sunny weather is preferred and that it is rain proof in 1/2 hour. This Roundup concentrate was good to clear out a decent portion of the unwanted growth, but not all of it. When I've used the Extended Control Roundup concentrate, it has killed everything and much quicker and lasts for at least 4 months, which is not good if you want to re-plant the area sooner than that, but is good if you're looking for a long-term cleared area. Based on my experience, I would be hesitant to recommend this Roundup Super Concentrate Grass and Weed Killer, unless maybe if you were only going to use it on a grassy area with no or very few common weeds.