I don't get pinging in my '12 either, polaris, and I run 87 octane...during the winter some of it is even in the '86 octane range. Even with my travel trailer hooked up, I get no pinging. The knock sensor and other components in the ECM system must be pretty good at doing their job. Generally there is some power and fuel mileage gain in vehicles like ours when using higher octane fuel because the timing and other factors can compensate to take advantage of it, but it's usually small.
Blog, I would think your '09 is very similar to the '12 in its timing and detonation issues, but I'm not positive of that. Plus, isn't the '09 Power Wagon quite a bit heavier than the regular 1/2 ton Ram pickup? Maybe that has some bearing too. I also wonder if you have some combustion chamber and/or piston crown buildup and deposits that are affecting your detonation issue? I've seen this happen on some vehicles with some mileage on them. Detonation is also sometimes caused by a breakdown in the ignition system. How old are your sparkplugs?