Turkey legs will only be a problem if the outer skin is really tough, or if you decide to chew on the bone.
The pain when you get them on is based on how much your teeth move initially and your pain tolerance. I had a heat activated wire, so when it warmed up in the heat of my mouth it started pulling. I also got them put on in December, in NH. So if I went outside the wire would freeze, and then when I went inside a building it would heat up and pull again. THAT was painful. My stepsister on the other hand had no pain. But she's a hockey player and has massive pain tolerance, so that could have been the difference. Different wires too.