All we can do is use studies along with our own experiences, experiences of family and friends, to gauge how a drug works. I went to a large university and Adderall was commonly used to study. Lacking a deep focus is only a problem if you decide it is. Brain damage is a problem, regardless of ones' opinion on it. And narcolepsy is too. Any serious physiological condition, is pretty much a problem regardless of what the patient thinks. However, the problem that ADHD is prescribed for, is mainly a lack of focus, a lack of "inner thinking." Which is really just a slight intonation in the brains' reward system. These kind of behavioral issues are mostly well-solved using CBT, cognitive behavioral therapy. Which can be done at home via standard pavlovian style reward/no-reward trials.
The reason psychiatric treatments require experimentation is because most psychiatric drugs are poorly understood in their mechanisms. We use them mainly because of pragmatic effects - not because we actually know their precise mechanisms.
I never said my experiences are universal, just that amphetamines have a markedly simple mechanism in humans and other animals -- that is, increasing dopaminergic activity, along with noradrenal activity. It is common knowledge that by increasing levels of dopamine, harder tasks can be performed without as much exhaustion. But mind you, the body's energy supply isn't unlimited - and though the mind might be more resilient, the body still pays for the extra activity done under guise of ease.
It is clear that you find the tradeoff worth it. Like you said, everyone has different experiences and finds different tradeoffs worth it. For me, the tradeoff isn't worth it - I find that taking amphetamines daily extracts most of the beneficial effects into tolerance, and what follows is pretty much just maintanence. If you find the tradeoff worth it, then clearly you should be using it. Only you can decide whether you are getting an overall positive effect from a narcotic that provides both positive and negative effects.
My main point is that we cannot deny that amphetamines are hard drugs - narcotics. And thus, it seems wrong to give them to kids with such ease.