I disagree. Consider a magic potion which allows you to suddenly gain inhuman strength. You drink this potion, and lift a stone you couldn't have hoped to lift beforehand. However, next to you is a man who doesn't have the potion, but has struggled, for a decade or more, to become as strong as he possibly can. He, too, lifts the stone that you have just lifted, without any exterior aid, though with greater difficulty. There's not all that much difference between exercising the body and exercising the mind - the benefits are manifold, and include not only production through action, but also growth with experience.
In my view any spiritual sort of strengths tie in intimately to the paradigm, personality and free will of any who realize them, so in other words no line can be drawn between the objective 'results' and the subjective work towards those results; the strength lies not in a given instance when you might manifest it, rather it lies in the fact that you can do it, a fact which necessitates that you've established certain modalities within your being as an individual agent of consciousness, you've structured or created yourself in a certain way. I would, for example, contrast this with most magickal powers, which can be cultivated through study, memorization and experiential practice but which don't require you to permanently structure in certain specific ways the fundamental correspondences between your emotions, desires, intentions and beliefs. To give a spiritual example, it's relatively easy to conjure up ecstatic feelings similar to drug-induced feelings, but unless there's a meaningful underpinning to it in terms of your beliefs and intentions then ultimately it's only a pleasant feeling and there's nothing transcendent or greater about it than that. In fact, as it relates somewhat in this vein I think, I would judge a person's level of enlightenment not by dissecting the contents of their highest highs but rather by disecting the contents of their lowest lows, to see if their enlightenment ever 'breaks' under certain conditions. Now anyways, I'm not saying there's anything necessarily wrong with magick, but I just want to be clear about what exactly I'm referring to. Combining the entheogenic experience with magick is a whole other kettle of fish I suppose, one I know less about, but I know enough to say it's definitely riskier, and perhaps can generate substantial gains if successful.