OK, just completed a highly scientific experiment. As mentioned above, the Smuckers ingredients are listed only as "peanuts, contains 1% or less of salt". The Great Value ingredients are listed as "roasted peanuts, sugar, contains 2% or less of molasses, hydrogenated vegetable oils (rapeseed, cottonseed, soybean oil), salt", but also has "ALLERGY WARNING: CONTAINS PEANUTS, MAY CONTAIN TRACES OF MILK, EGGS, ANCHOVIES, WHEAT AND SOY". The only thing that surprises me is "anchovies"???? Both jars of peanut butter were the "creamy" type.
But to continue . . . when my wife saw me opening 2 jars of peanut butter, and putting the dough hook in the mixer, she asked, "Are you fixin' to make a mess?" and I replied, "Quite possibly". As it turned out, no mess at all.
First I mixed the Smuckers pure peanut better that had oil on top when I started. Even when I turned it up to the 7th speed, no mess. When it was thoroughly mixed, I washed the dough hook, then did the same mixing to the Great Value peanut butter. Then came the taste tests; my wife and her sister participated.
And the conclusions; the pure peanut butter was slightly thinner in texture than the other, and all 3 testers agreed that the pure peanut butter tasted better. So I reckon we'll only buy the pure peanut butter in the future and mix it when needed.
And we thank sixdogs for starting this thread with good information.