One post said get the air suspension, well I have it and its great to hitch and un-hitch. But it still rides like a truck, loaded or unloaded. I had a 3500 , and traded it for this 2500 diesel when I downsized my RV. Honestly wished very much that I would have kept the 3500. This coil suspension when loaded feels like its floating from side to side at times? One of the best features besides the power of the diesel, is the exhaust brake. It makes towing so much easier, and its seamless to use. I only really use my truck to tow my RV. Its not a DD. So when I do use this truck it under heavy load, so the emissions issues hasnt been an problem yet.
I get consistently 12mpg, when towing the RV no matter the speed. My other Gen4 3500 diesel, got 10mpg, when towing.