The Spartan can run in rougher water than the UL-1 so he's got the edge there. The UL-1 can be no sluch though with the right battery packs and prop on it. There's a few other low-cost if not free ways to make it faster and more stable. You'll also be stuck with mostly making right turns as that's what it's made to do whereas your buddy can turn both ways a lot easier. That boat has been known to make 60+MPH runs with the right setup. That was from someone who knew what he was doing though but it was still with the stock electronics.