Only issue with torsion axles is that the trailer needs to be LEVEL, not close, but really level. If it is not the "lower" axle will be carrying more load. Thus tires wear more, blow more, etc. With leaf springs, sight nose up or down is compensated for by the equalizer beam between the front and rear springs.
I given a choice, would prefer torsion axles or some sort of independent suspension, but it requires attention to details.
'03 Ram 2500 CTD, 5.9HO six speed std cab long bed Leer top and 2008 Bigfoot 25B21RB.. Previous, Being repaired and will be sold, is a 2008 Thor/Dutchman Freedom Spirit 180. SOLD - 2007 Winnebago View 23H Motorhome.