I would suggest to go look at both of them. They are both excellent trucks for that price range in both durability and build quality, in crash test it was second right behind the Tundra. But it ranks a lot better than F150 or Ram.
GMC's are kind of like the upscale brand, just like Trans Am is the same car as Z28 but the T/A comes with better seats, interior trim, little things Etc. Also they come with different options and interiors.

The new Silverado front ends look BAAAAAAAADDDAAAAAAAZZZZZ