What Are the Differences Between the GMC Canyon and the GMC Sierra 1500? Photo: GMC If you’re shopping for a GMC truck, should you choose the 2021 Canyon or the 2021 Sierra 1500? With the Canyon, you’ll get a smaller, less expensive truck that can still handle routine towing, hauling, and recreational activities. The Sierra 1500 is pricier, but with the expanded power, capabilities, and features to match. Photo: GMC Size As a full-size pickup, the Sierra 1500 is longer, taller, and wider than the midsize Canyon. The Sierra comes in three cargo box sizes, all of which offer more cargo volume than the Canyon’s two box sizes. Inside, the Sierra’s crew cab and double cab configurations offer a more generous amount of second-row headroom and legroom.