I use them (among other things) and like them very much. The legs on mine (from Premier) are a little bit more delicate than I'd like, and I cracked one. I can't find a replacement but DH says he will make me one someday. I do not use the special cap to keep the chicks off the top, but I do sometimes cover it with self stick plastic wrap. The babies LIKE to sit on the top as well as to go underneath. I use them inside and outdoors. One advantage is that they do not draw a great deal of power compared to brooder bulbs or a large size heating pad. Since the model I use has four independently adjustable legs, I usually set it up on an angle with the back portion lower, thus warmer, than the front. The chicks arrange themselves in its warmth according to their need.