Can't argue with that either. As I've always understood it W231/HP38 (same powder under different brands/labels) was specifically designed for 38 special (hence the "38" in HP38).
It also meters better than Unique. Not quite as versatile as Unique though.
AA#2 is another one that I like for 38 special - and 9mm, and 357 magnum, and 44 special, and 45acp...