I would go with the Hughes. Service and repair costs are cheapest compared to the other two. They told me theyre always looking for ways to improve their internal components. Also, Franks and SurgGaurd ripped off the hughs original patent. I would stick to the original. Some of these last forever, some of them dont. Its not due to whats put in them, but the amount of abuse they take in different parks. They were also very nice to me. They also explained that their newest generation autoformers can be calibrated, but come standard boost at 114 and stop at 116.