Product review (5 stars): Extremely useful for the home chef
For the price, this item does exactly what I want from it: diffuse heat.  Great for keeping leftovers slightly warm, keeping things from getting too brown, etc.  I really like to use it when I'm prepping dinner and have several things going on at once - I can prepare one part of the meal, toss this on the burner, turn the heat to low and help keep it warm (but stop it from actually cooking more) while I do other things.