They didn't hold up well on gravel, the seemed to wear really fast, and they got very loud as they wore. They also would also cup worse than other tires in my experience. I see a lot of our work trucks, and even with regular alignments and balancing, the Duratracs cupped far more often than others. We're also not easy on our tires.
I haven't seen any of these behaviors with the new RT. Of course, without balancing, alignment, and rotation anything will cup and wear poorly. The RT also seems to have better traction across the board. I've never understood the love for the Duratrac, but that's just me. But for that matter, I've never understood the KO2 love either. They did fine but are ugly (IMO) and didn't perform better than some cheaper tires. The Cooper AT3, Falken Wildpeak AT3W, and honestly Firestone Transforce AT2 all performed just as good if not better and are generally cheaper.
When I bought my new (used) truck, the dealer had just put new RTs on it and I've been very happy with them on there too.