Tell you what, I have towed with my parents 2012 duramax 3/4 ton, my grandfather's 2006 durmax 3/4 ton, our 2002 dodge dually 1 ton farm truck, and our 2013 dodge dually 1 ton, and this 1/2 ton pulls that 20' steel gooseneck stock trailer like nothing. Its just a curt under bed gooseneck hitch too, nothing fancy.
When you load it up with 10 or so 600lb yearlings its working, but it not dogging it. I don't drive like a raped ape either, empty i'll drive 110km/h and loaded i'll drive 90-100 depending on how windy it is. Side winds really suck the fuel, something like 25-29L/100km, but when there is no wind or a tail wind I typically get 21L/100km.
Air bags are a must though. It doesn't squat it down that much when its empty, but when you get animals that like to stand at the front of the trailer and not evenly dispurse some of the weight over the axles it will squat it down a couple inches with out air bags.
All and all it hauls pretty good. By all means it ain't no duramax, but when its within the GVWR, its pretty hard to justify spending $45g on a 1/2 ton that can tow what you need, than buying a 3/4 ton duramax for $75g.