The dispatcher has been my kill-method of choice ever since my RIR hen suffered a viscious attack from a large owl (she had been blinded in both eyes & had other severe facial injuries). She was bleeding and shrieking and the whole thing was truly horrifying. It was obvious she could not be saved (and I AM one of those crazy people who will take a chicken to the vet & pay hundreds of dollars to try & fix it). At 2AM, what do you do? We don't own a hatchet, and her head, well, there wasn't much to grip for a neck break. Ironically, the dispatcher had come in the mail just the day before & was in the kitchen, and I used it and put Henny down. And it was quick and peaceful.
If you're processing though, you probably want that blood drained out while the heart's pumping, so a knife stick while they are in a kill cone or a head chopping off is probably the best method.
For humane culling without trauma and mess, I like the dispatch tool.