I can't say that I have. Be cautious about making these judgments. For example, someone flock mating may have a subordinate male that sneaks it in every now and then. He is not going to take the time to go through the motions, etc. The hens are going to be less likely to submit to. This is not a behavior problem, this is normal behavior. The hen might cry fowl, but for him it is surviving. It would be easy to assume that there is something wrong with him. For all of the complaints that I have heard about "proper roo behavior", I have rarely heard mention any consideration for the way that they are managed. Even a bird that does "do his dance" does not necessarily do it all of the time. There is the danger of crossing the line, and crossing into picking gentle birds that is more about our world view and perception. It is an unnecessary burden on us as the selector, and them as the birds that will never conform, or behave the way we think that they should. Calm and gentle, just as often means lethargic. I have had a couple birds along the way that were absolute nut cases. A terror to their flock mates, and to the keeper. There is no good reason to keep a bird like this, unless you want more of them. There is no good reason to keep man fighters, unless you want more of them. I would say to select against extremes, and otherwise worry about health and vigor. These extreme behaviors seam to be more common among hatchery birds. This is not to pick on these, because it is as often not the case. It is just that when flocks start numbering in the hundreds, the birds are under a lot of stress, they are crowded and over stimulated, and it is survival of the "fittest". Over many generations this could have an effect on who is represented in the offspring. There is nothing "normal" or "natural" about these settings. Then after countless generations, should we expect them to behave "normally" or "naturally"? The good news is that most chickens act like chickens.