The "water is cooler so it won't warp" is marketing hype. Media hitting the panel is basically many tiny hammer heads hitting the panel. Too coarse of media is basically using larger hammers. Too high a pressure, whether that be using air or water pressure, is just swinging those hammers harder. Warping occurs when the hammers are too big or swung too hard.. has nothing to do with heat. If the panel gets hot it is from the peening action. Take a hammer and pound on a piece of sheet metal on an anvil and it also gets warm. But just like media blasting, the panel stretches long before the heat shows up.
The biggest detractor for using the dustless blasting is that the slurry that it makes winds up in nooks and crannies and is difficult at best to remove. So now it becomes the next moisture trap for starting more rust.
