I can confirm that a true 5 speed hell horse does indeed go faster then a 4 speed without the rare speed trait. I'm not aware of your auction, but sadly people like to put out misinformation pretty often. Now one thing to keep in mind, and again I don't know if it was said in your auction, but I know that 90% of people use hell horses for carts/wagons. In the the case of carts and wagons then no speed trait is going to matter, as only the draft traits work, so in that instance a 5 speed would not work for a hell horse, so there could have been some confusion on that point. Also concerning that, the extra boost for being molten does not matter for carts/wagons as it is a speed modifier and does not apply to draft horses when hitched. So all color drafts pull at the same speed.