Firstly, I think you're seeing the old magnum trucks through rose colored glasses. We brought a ~2500lb boat/trailer combo up from Alabama, and on the gentle rolling hills heading north, my buddy's 97 ram 1500 5.2 was a total dog, either constantly downshifting or we had to let it lose 10mph on each uphill to prevent it from dropping 1-2 gears. And it was a fuel hog while doing it.

Also runcharger, this year I visited Surrey for the first time. Very hilly area, especially compared to the flat lands I'm used to. I will say I was thankful my wife's Mazda 3 we were driving is a stick shift. I imagine an auto trans anything would feel like a constantly shifting gutless wonder when dealing with those hills. I've never been to Kelowna, but if your area is much the same, I would expect you're accustomed to your diesel which would have had the torq to do the job without all the shifting.

Also, FWIW, a co-worker of mine was recently telling me of how he "upgraded" from his 03 Chevy 2500 6.0 gas truck to a 13 Chevy 2500 6.0 gas truck. He said he's dissapointed in the new truck. He says it has more road noise than the old one, rides rougher and is constantly downshifting compared to the old one. My guess is the chevy trucks just got fatter like the dodges have.