I think YHR nailed it. Tanks are metal, that's that. Whether that's needed or wanted in 1:16 scale is beside the point.
It's attractive, especially if the price is right, practicality be damned!
Definitely some added challenges to working with this sort of material over plastic or even aluminum or steel.
Curious if the weight of the tank is suspended at the four corners via the dampeners (like the HL and Asiatam setups) or if the dampeners are not spring loaded, and all the torsion bars are actually doing the work they should be.