If you think the Ford F-150 SVT Raptor is too hot yet the Dodge Ram Power Wagon is too cold, General Motors’ latest concept might strike you as “just right.” This, the GMC Sierra All Terrain HD concept, looks to bridge the gap between the two hardcore pickups from GM’s crosstown rivals, while still offering top-notch levels of power, refinement and technology.The four-door 2011 Sierra HD
