This thing is just great. Got it a week ago, & it's transformed my pizzas. You just need to read the instructions, & treat it with respect, as it gets up to the internal temperature of your oven's maximum ( ours is a fan/convection, with a max. convection of 350C.... pretty hot ).
You just stick it cold in the cold oven, turn heat to maximum, wait 45 minutes til til maximum's achieved, carefully throw or peel your pizza onto it, then watch it like a hawk through the oven window for 10 minutes as your pizza fluffs up but crisps on the bottom, just like a restaurant-bought one.
That's if you like crispy bottoms. If you're a Pizza Hut afficionado, & like soggy bottoms, don't get one.
It also cooks steaks in foil, fish in foil, bread rolls, etc., with both sides being evenly cooked in record time.
One of the best cooking aids I've ever bought.