I was thinking of getting an Allied Heated Pet Bowl - Plastic or pretty much the same thing in metal "Heated Pet Bowl - Stainless Steel This bowl will keep your pet's drinking water ice-free all winter long. The heating element is removable for year-round use. Thermostatically controlled using only 45 watts of power, it holds 1 1/4 gallons with a 70" cord. Dishwasher safe. " Is the metal worth twice the price? I liked these (heated dog water bowls) since they seemed to be more powerful than the poultry ones. They are made to be outside, but they still seem very safe. Comments?