The new Square units offer a larger cooking surface, as the upper racks are the same size as the lower racks. The firebox is insulated on top and front to extend paint life, increase efficiency and reduce burn hazard. The cook chamber doors weigh less and the unit is much easier to clean. The water pan option is strongly recommended on the new units as it also serves as a charcoal grill option. Please give us a call to inquire about the benefits.