With most foods, the raw version is the most nutritious. Not the case with the agave plant. Is raw agave nectar truly healthy? That's it's touted as. But if you look at the antioxidants in the plant, the cooked version has over 2x that of the raw and the dried version has over 500% more than raw. Now to be clear, this comparison can be misleading because those two versions which test higher are concentrated, since they have less water than a raw agave plant.
Even ignoring that comparison, if you compare raw agave vs. sugar and other sweeteners, it doesn't turn out to be as healthy as you may think. Sure it has antioxidants (and table sugar doesn't) but it's glycemic impact is not necessarily as low as some people assume. Or more accurately said, the reason is because the GI is not looking at the fructose content. Regular table sugar is about 50% fructose while agave (in the processed forms - i.e. syrup or extract) is 70% to 90% fructose.
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010