Perfect for a DRK Dark Magic+ build. On HNM skill+ is often more effective than Magic Accuracy, giving this an edge over Corselet. Also, this is a lot easier to obtain, and more than likely cheaper as well.
Since there are no Body pieces for DRK that give a Haste or Fast Cast benefit, you can consider leaving Turban equiped (rather than changing to AF helm) to aid in keeping the recast time to a minimum.
Whilest this piece of equipment isn't a necessity, it will be a great help if you lack Dark Magic merits when trying to steal the TP from those pesky Mamool.