I have a collection of sunlight equipment that I have used extensively for over 25 years, always with aamazing results, and few , if any, problems. There is nothing that I know of that can supply the combination of short duration and power that this system provides. I also have a model A901 that I think was made on special order with two heads. I have shot extensively with this unit at 5-10 frames per second. I would love to talk with anyone who knows more about this unit or the sunlight system. It's all about to go into storage, unless someone out there wants to give it a good home. Maybe the Smithsonian.......