BGE Ceramic stones

After reading the forums for a while I think people might be thinking too much about their pizza stones.  The purpose of the stone is to provide a consistent temperature-stable cooking surface for the bottom of the pizza.  You put it in the Egg and let it heat up while the Egg is coming to temp.  When you open Egg and throw in a piece of cold dough, some of your heat escapes but the stone is not going to cool significantly (due to thermal mass) and the air that escaped will be replaced with hot air in a matter of minutes. 

Back in my pizza shop days (see profile pic) we had gas-fired Bakers Pride ovens that had a 3 inch thick slab of stone between the burners and the oven space.  The ovens were set to 650 degrees.    Opening and closing the oven doors to cook the pizzas would eventually cool the ovens slightly but it took several hours during the "rush' on Friday nights before the stones would start to cool and slow the cooking time.

With all that said I think a thicker stone might enable you to cook several pizzas back to back over a longer time due to its mass.  I currently use a 1/4 inch thick Pampered Chef stone we have had for 15 years because that's what we had when I got the Egg.  I'll replace it with a thicker stone when/if it breaks.  So far I have cooked three 12 inch pizzas a week @ 650s degree since November 2011 and the stone seems to do the trick.  I place platesetter legs down, then BGE grate then stone.  I found placing stone directly on platesetter makes the bottom of pizza cook faster than the top so I add air space.  You need to experiment with your stone and your cooking temps.  You can also use canning jar rings to space stone (or a drip pan) on top pf platesetter.

HTH,