It is likely the Scotts product is better. They are the top brand name, and work to protect their reputation, and support their higher price with advertising. Take a look at the percentage of slow-release nitrogen. It will usually be about half of the total nitrogen, sometimes less. Say if it has 26 percent nitrogen, about half will be in a slowly available form sometimes more like a third. They may word the label in a way that makes it appear like more. Scotts sometimes claim that their form of slow-release is better than sulfur coated nitrogen of the second tier brands.
Stagreen probably uses dithiopyr crabgrass control. I am not sure if Scotts is using Pendimethalin or has changed to Tenacity (mesotrione) active ingredient in their Halts product.
In either case if they use the minimum allowed amount, it may not last through the whole season in a warm location like NC, and if the temperature has hit 80 so far this spring--you may be too late.
and...keep in mind crabgrass control will not usually control broadleaf weeds--which you mentioned first.