I bought the 13" pizza grill 2stone last year and this year I sprang for the 15 1/2" pizza grill. If I had to do it over again, I would have bought the 15 1/2" from the get-go. It works like a dream. The 13" cooks fine, but maneuvering your paddle to get the pizza to the stone is much more difficult, even though you may only be working with a 12" pizza. Both work great at cooking pizza, but the 15 1/2" is just so much easier to use.