Poll: ¿Is animation-direction a good idea?

Summary:
¿What’s the animation-direction property?
¿Is alternate reverse and reverse alternate (either would be allowed) a better value for animation-direction over alternate-reverse?
¿If so, should redundant combinations of normal with alternate or reverse also be allowed, such as normal alternate?
¿Or maybe we should ditch it altogether and replace it with animation-reverse, accepting values of none, all, even, odd?