I agree that Paul Buff gives comprehensive, good information about their own flash units and it would be good if others followed their example. I don't have any of their units but some of my friends do, and they appear to be excellent value for money.
The thing is that at a claimed 42 lumens per watt they aren't really any more efficient than units from manufacturers that do not inflate their ratings. That's where the BS creeps in. They do not explain what the 'effective watt seconds' is based on. What is the origin of the 17.5 lumens per watt efficiency that they use to calculate their effective watt second ratings? A 60 W household incandescent lamp? - because that's what it is equivalent to.
One of the ways that manufacturers can improve the efficiency of a flash tube is to operate it so that it produces a higher correlated colour temperature than required, then reduce the CCT with a filter. This is quite normal practice.
One could make a comparison with dedolights. Thanks to superior optics, a 650 W tungsten dedo is more efficient than a 650 W Arri Junior - what you could call the industry standard for tungsten fresnel instruments. Dedo do not call it a 1200 W effective, they call it a 650 W.