Two days later:
Hadn't run barefoot for a looong time. Got a dec quarter sized blister, but that's not a bad thing. Looks like a form inconsistency...left foot lands too straight and initial ground contact is too far forward...right foot is a bit duck toed, probs resulting in the little bit of pain I get on the inside right, right behind the ball (PF?). Stride frequency decreases in the Newtons. Not a terrible thing, but BF definitely looks best.