I'm getting ready to buy a 16-18' trailer so I can haul a small 30hp 4x4 tractor with front end loader. I was thinking about a new steel power coated trailer, but I found a used aluminum trailer locally for the same price. I've never owned an aluminium trailer before. One disadvantage I see, is if you want to do any welding to add something you would need a heliarc welder, which I don't have. I know light weight and no rust are the biggest advantages.