No doubt they're very nice trucks, and probably more durable than a 1-ton class dually in terms of durability. The frame is larger, larger axles, brakes, and an engine with lower state of tune (8.3 ISC making less power than ISBs in pickups).
However, in terms of pure PERFORMANCE, it will be out-classed by the latest 400+ hp duallies. Its GCWR will be less than the latest Ford / Ram duallies, while giving up around 100 hp.
For the price, I'd be inclined to get a Class 8, and single it. Now that will out perform any 1 ton dually! MPG will be a wash as you're not running a torque converter automatic, especially if you stick with a "small block" engine (12 - 13L).