Finally, data from studies comparing the two amphetamines on measures believed to be predictive of abuse potential (i.e., drug discrimination and self-administration) indicate that equivalent doses of the drugs produced similar responses, further indicating that the drugs are equipotent 11,12,13

In my experience, as a daily (prescribed) d-amphetamine user, there is a clear difference between d-amph and meth. I don't experience any increase in positive effects of d-amph past 50-60mg, any more than that and i only experience an increase in negative effects like anxiety and uncomfortable peripheral nervous system effects. D-amph also makes me far more motivated to do tasks which I would normally procrastinate over.

Meth on the other hand(don't know if it's d-meth) does not give me much motivation to achieve tasks, it makes me more content and happy doing whatever im doing at the time, and i think it actually encourages me to do more hedonistic activities. Meth also destroys my motivation far more than d-amph ever did. I did a few grams over a few months last year and in that time I gave up exercising, eating healthy, and contrary to what most would expect I gained about 20kg. It took me months to realise how much i had let things go and get back to living a healthy lifestyle.