I have used a Calicrate bander and like it very much. We usually band at birth on commercial calves, and sometimes do another sort in the spring and use the Calicate bander for them. I have never had an animal get sick, go off feed, or act different in any way. In fact, I have seen large feedlots use it on 18 month old bulls and they have continued to gain as good as the steers they were being fed with. We have a 15,000 head feedlot near here and they use it routinely and have never had problems. My vets actually suggested it to me and they told me it is an excellent way to castrate older animals.
I have watched many animals that were banded at an older age, and I have never seen one that does not act normally. If I did see any signs of distress or reduction in feed consumption or gain, I would probably never use it again. But until that time, I will use it. Our vets routinely use it on older bulls that go to feedlots and they say they have not seen any adverse affects. They also use it for dehorning animals with large horns and they really promote it for this as well.