I'm like a few others here and don't tow anything massive (27' Coachmen Apex), but towing with our old 1/2 ton (Tundra) was less than pleasurable. Once we got the family loaded up and gear in the bed we were definitely over payload. Everyone likes to get on the forums and say "I can't even feel it back there!" when they tow a 10k lb travel trailer with their 1/2 ton—yeah, sure you can't... I could have gotten away with a 3/4 ton, but after driving one of those and a 1 ton I couldn't notice a difference, so only costing about $1k more I just went with the 1 ton gasser in case we ever get a larger trailer.
Anyway, towing with this is MUCH better, and the 10 speed has been fantastic.