Clever, although not quite a pizza oven, keeping the lid on allows for hotter temperatures:
My wife just sent me the same link. A promising idea, I think.
I just so happen to have a Brinkman "kettle" that has an extra segment/extension like this, sans the slot. It was intended for smoking, but never worked very well for that. No reason why the tinsnips and angle-grinder can't cut a slot and we'll see...
Don't waste your money.
Grill scenarios, with bottom heat sources, always have top heat issues- the bottom of the pizza will bake/brown faster than the top. To compensate for this, you want to lower the ceiling on the grill (usually by adding a false ceiling) NOT elevate it with an insert. The further the ceiling is from the pizza, the less radiant heat it gets, the less top browning.
This under-researched contraption will guarantee pizzas with white, undercooked tops and black undercrusts- every time.
I don't know about this gadget, but your categorical statements are incorrect. I use a 16" square pizze stone on a Weber Genesis grill. I preheat the stone for about 20 min. Thin crust pizza comes out just right -- nicely toasted on the bottom of the crust, nicely browned on top. Of course the heat source is below the stone, but the grill top is closed so there is some heat from above. After sliding the pizza onto the stone, and closing the lid, it takes 8 to 9 minutes for the pizza to be done.
If you want a little bit of smoky flavor you can add some wood chips.
I'm sure a separate woodfired pizze oven costing a few thousand dollars and taking hours to heat up could be marginally better, but I've had a lot of wood fired pizzas and I can tell you this method is very very close.
Pizza from wood fired ovens in the Neapolitan style are cooked in 60 to 90 seconds. By virtue of the time difference one could conclude that cooking on a stone in a Weber for 8 to 9 minutes isn't going to produce a product that is very close. At those times you might as well cook in a regular oven.
Except that cooking at high temperatures in most home kitchens is a pain in the ass -- if you don't have an expensive (and noisy) vent, there's smoke, alarms going off, etc. Making pizza on a Weber grill (I can't speak about other types) works just fine without the fancy gadget. Or even pizza stones.
I can't say if it works or not, but did you actually go through the web-site and read how they say it works or is your post just based on generalities? I understand what and why you made the above statements, I just wondered if what they had to say had any influence on your opinion or not.