I like the Miller/Howland design selection in the safety slide. For me it is the only possible design that can allow one to actually select when a bird is on the wing. Certainly can't with a Parker Bros., Fox-Kautzky, or a Hunter One Trigger selector.
Don't get me wrong, I like it too. I just think it requires an intimate proficiency with it or it's likely to be unknowningly set to fire the left barrel in lieu of the "safe" position in hunting situations.
I do think that the later Miller selector and the M21/SKB type selector work well for bird on the wing selection.