#1 has the most organic form, elegant distribution of niku along the mimi. It's thin where the branches seem to want to push out of the form. The mimi also accentuates the form better than the other examples.
The completing of the seppa with sekigane is - I think - an early afterthought to its creation or even an initial part of it. The curvature of the underside of the pine bushes suggests more movement than the others, creating a sense of wind, which is enhanced by position and form of the mimi, where #4 and #5 are more static. Very free, creative design. If I didn't know the maker, I would say Kanshiro.