All racetams, for me, are closer in effect than comparing Tylenol to a laxative or LSD to caffeine though... You already seem aware of all the background, as you've just posted all the varying doses, so yes clearly you are correct in one way, but they are not completely baseless IMO. It's there for marketing I'd say yes, but it also can have basis in reality depending on the claim(here is an example of how one paper came to a x times more potent conclusion http://www.ncbi.nlm....pubmed/12070754 another: http://www.ncbi.nlm..../pubmed/8277504). There might be ones saying the same for piracetam compared to aniracetam etc, I don't know.
OK, I can use a more related analogy.
Anecdotally, piracetam's effect on multitasking is nullified by aniracetam's effect on single-minded focus. Oxiracetam is purported to give a feeling of energy and motivation (which I agree with), while pramiracetam is purported to cause clear-headed thought with occasional drowsiness (not all people experience this drowsiness, apparently). These are only a few examples of qualities which are primarily antagonistic and mutually exclusive.
If I were to market Sleep Aid (diphenhydramine HCL) as being "3x More Potent Than" No-Doze (Caffeine Anhydrous), this would be considered misleading, because these two substances cause roughly opposite effects. Caffeine blocks adenosine receptors, thus inhibiting the inhibition (nope, not a typo) of various neurotransmitters (including acetylcholine), which causes increased alertness and neural activity; while diphenhydramine HCL blocks histamine and acetylcholine receptors, causing decreased alertness and neural activity. However, it should be added that these substances also cause many of the same effects as one another (flushing of the face, irregular urination, twitching, increased heart rate, pupil dilation, cardiac arrest, etc, etc).
Just because two substances happen to cause some of the same effects as one another, does not mean one should specify that Supplement A was "X times more potent than Supplement B", unless the
primary effect of one substance is greater than that same primary effect of the other. Conversely, one could say, "Supplement B is 4x more potent than Supplement A when used as an anxiolytic"; this would be a completely acceptable statement. Even though the primary effect of Supplement B may not be greater than the same primary effect of Supplement A, it has been specifically stated that the effect we're concerned with here is anxiolysis.
Your two references strengthen my point: both of them specifically state in which effect a given supplement is "more potent" than another.
If any specific racetam is "x times more potent" than another, I should like to know in what respect it is more potent...certainly, this must be describable, otherwise the assertion is useless and unwarranted. However, I have never, to my recollection, seen anyone specify this. On the contrary, I have always seen simply "Xracetam is __times more potent than Yracetam".