I didn't do the math or anything, but the slices on the $4 pizza look to be the same size as the slices on the $5.55 one. The $4 one has 6 slices rather than 8.
squares is only for thin crust. those pizzas are disgusting...they use cheaper sauce, which is really sweet and cheaper cheese...it tastes sweet, pizza is not supposed to taste sweet. pan pizza at pizza hut is awesome but stay away from those pizza mias..dominos uses the normal stuff on all their pizzas...which is why its a little more expensive. You can also get this deal for lunch no coupon needed just let them know you know about it and they'll have to give it to you
What's funny is they make it sound in their commercials that the Pizza Mia Pizzas use better ingredients than their normal pizzas.