GMC Sierra 2500HD (2017) is 394 mm (15.51 inch) longer, 6 mm (0.24 inch) wider, 51 mm (2.01 inch) higher and has 305 liters (10.77 ft3) bigger cargo space than Nissan Armada (2018).
Nissan Armada (2018) is 75 kg (165 lbs) lighter than GMC Sierra 2500HD (2017).