axles
Torsion axles have been around a long time. Used mostly in European countries. Far more stable thatn a sprung axle. Currently many of the trailers used the United States Military have dexter torflex axles on them.
They can be modified to put shocks on them if necessary.
They have great warranties on them, and truly are bullet proof. I have only heard of one failure, reported by AT. In building trailers with torsion axles well over 400 trailers, ranging from 5th wheels, to expedtion level trailers, I have never seen one fail from natural use or causes. I have seen them involved in accidents and destroyed. I also have seen tandem axle torflex axles lose a wheel and the owner never even knew it.
They also make the trailer considerably stronger on a standard tube frame.
I would choose them or something like AT makes over leaf springs anytime. My concern with the air bag systems is puncture, but in honesty have never seen that happen.
Hope that answers some of your questions.
Torflex axles offwe what is considered a 6 inch drop, which can be lowered even more to provide tremendous ground clearance.
Have fun.