I've towed 15,000lbs gooseneck with my 2500 6.4, 3.73 axle. The 8 speed transmission helps a lot. I'm operating in hilly / mountainous NH / VT. Up any significant hills, the pedal is to the floor and I may not be able to maintain the 55mph speed limit and the engine is screaming. That said, I'm not sure the 4.10 would really do any better. If your engine is wound all the way out going up a hill, a shorter axle ratio just means it will be screaming in a different gear, which might be slower. Perhaps 4.10 would take off from a stop better, but I'm actually pretty satisfied with how the 3.73 axle and 8 speed steps off from a stop.
I had an F-350 with the 6.2L gas V8 and the 6-speed transmission and 3.73 axle- this truck does better. Perhaps its because the Hemi makes a little more power and torque (I had the 2015 version of the 6.2L which made 405lb-ft, not the current 430), but I suspect it has more to do with the 8-speed and maybe because the Ford 6.2L was OHC and needed to really wind up to make power.
I had an F-350 with the 6.2L gas V8 and the 6-speed transmission and 3.73 axle- this truck does better. Perhaps its because the Hemi makes a little more power and torque (I had the 2015 version of the 6.2L which made 405lb-ft, not the current 430), but I suspect it has more to do with the 8-speed and maybe because the Ford 6.2L was OHC and needed to really wind up to make power.