I have 13 chicks, with the x-large sunbeam heating pad, currently on 6. I'll turn it down to 5 in another week and continue turning it down weekly, as long as they are happy. When they go under at night, not a peep is heard, so I know they're fine. I would think all heating pads are equally effective, as long as they will stay on constantly. The chicks will let you know if they're not comfy.