It's magic pixie dust in a few cartridges. In most it doesn't get any more velocity than other powders.
Of course, if there's no pressure-tested loading data ANY powder can be magic. One of the reasons Reloder 17 acquired such a magic reputation at first is Alliant released it before much data was available, so handloaders got to "work up" loads the old-fashioned way, by adding powder until the rifle/case showed signs of stress, then backing the load down "a little."
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
