Suck. For me. Does anyone get them to work well? I've got a case that is 10 years old so I'm eating that which is still palatable (most of it) but I've tried two heaters following the directions to the letter and meh.. neither one hardly did jack. I remember in the past never being impressed with them but these just flat do nothing, or almost nothing. Could they just be too old? I would think the heater would last longer than the food.