Anyone looking for a nice warm dogbox should look at http://patriotdogboxes.com/
The whole box is insulated with 3/4 " foam and wrapped in an aluminum skin. Very light, very warm. They have six vents, lockable top storage and winter door covers. All around good product and good company to deal with.
Pictures of mine are in the album under general.
nice warm dogbox
Overall construction is good, but because of the design I would guess that a diamondplate box is stronger, and more rigid. This box's strong points are it's double walled construction which has 3/4 "insulation on the inside and it's very light weight. The latches are good too, like a latch you see on a chain link fence gate. The door covers are aluminum sheet metal the same as the box cut and bent to slip over the door. The inside is bare metal. I have a piece of old carpet cut to fit the bottom and lots of straw in there. The website will give you a better idea than I can.