Nope, no erratum or FAQ for the archetype. I guess the upsides of the archetype are Rain of Blows and Dance of Fury, although the former is only really valuable if you don't have a party member casting Haste/Blessing of Fervor (and you'd still want to buy Boots of Speed). Dance of Fury is very potent, though, because the ability to move and full attack is a game changer for any melee. Note that despite the proficiency alteration and the name, the archetype works best with a longspear, in order to avoid provoking while using Dance of Fury.