Since the body converts ubiquinone into ubiquinol, there is an extra step involved, and not all of the ingested ubiquinone gets converted into ubiquinol. In healthy people, over 90% of the CoQ10 in the blood is in the form of ubiquinol, but as you get older, both the total level of coenzyme Q10 and the body's ability to turn it into ubiquinol decline (this is probably, although not clearly identified in research, something that begins at a very young age - like 20-25 years and continues to decline like the hormone milleu that you see with testosterone, et al...).
Note that this doesn't mean that taking ubiquinone is ineffective; all it means is that taking ubiquinol is more effective. If you are in your twenties, your body can probably convert much of the ubiquinone into ubiquinol, which means that you can save money and get the cheaper form (then again, this may mean that you probably don't need supplemental CoQ10 in the first place, although I am unsure given the effects, that you'd go wrong even in a state of "excess" although again - not clearly identified). If, on the other hand, you are over forty or concerned about your heart health, it may be worthwhile to go for the ubiquinol.
So how much ubiquinone is pure ubiquinol equal to? According to Kaneka, apparently the only manufacturer of ubiquinol, ubiquinol is up to six times as effective as ubiquinone in increasing blood levels of ubiquinol. So to get the same effect, you could take one sixth of the amount as ubiquinol compared to ubiquinone. But read the "up to" part of that statement; its long-since been suggested to use two times as much ubiqinone versus ubiquinol, but this number probably isn't that static.
D_
