+1 on the PCB Einstein. As I type this, I'm standing next to one with a PCB 48" Octabox mounted on it. I use the PocketWizard system, and consistent with others' responses, I have it set up so I use the lower end of the range (1/256 - 1/4 power), and I'm working at the lower end despite the large modifier. More power is useful outdoors to overpower the sun when using a large modifier, but not needed indoors, in my experience.