I am such a geek that I marked my garage floor with two lines ten feet apart to facilitate testing flash units. Now I have a quick and easy (and repeatable ) way to experiment.
I tried a Lumedyne flash vs. a Nikon SB800 and found that the SB800 delivered the same amount of light at full power at the the Lumedyne at 100ws. That means that the Lumedyne at 200ws is only one stop brighter than the SB800. You could compensate for that by increasing the ISO or opening up one stop. Nice to know and have in your bag of tricks.