Originally Posted by WNCGoater

Sorry I have to disagree. With clipless there is the option of switching to pulling instead of pushing the pedal, and this engages some different muscle groups, while offering a bit of rest to others. For me, it also changes forces against the foot which gives a bit of rest to areas of the foot being stressed. Heck, you can even unclip one foot, let it hang down off the pedal and pedal with the other if you wish!
Engaging some muscle groups while allowing rest in others by changing how you push or pull the pedal can indeed increase efficiency IMO. There is a reason toe clips came about in the first place and advent of "clipless" pedals.
But I suppose we would have to define "efficient" as it applies to touring. Does it mean faster? Longer distance? Less fatigue? Just easier? Seems easier at least, to me.
I do NOT believe "efficiency" means bunny hopping! nor do I believe that was the intent of the OP's question.

At the end of the day, for touring where one is typically riding moderate to long distances at relatively slow pace, I doubt there's much difference between the two, all things being equal. But regardless, everyone has to decide what they want, like, and what works best for them.