Mostly it is just exterior looks. From my experience, the 2 GMCs I have had, the interior seems to be more plush and more comfortable. Also, the GMC dealership seems to have better customer service than the chevy dealer that we have here. I did have a fully loaded chevy and didn't like it as much as my cloth interiored GMC. The GMCs that I have owned seem quieter inside too. In the end, it comes down to personal preference.