One is the DIYPC Gamemax-W (Full Tower) the other is the Cooler Master Scout (Mid Tower) but the mid is larger and has more space inside? Is this some kind of catch?
A full tower should support E-ATX motherboards and be over 22" tall. Generally over 3 external 5 1/4" drive bays as well. That DIYPC should be classified as a mid tower.