To compare the 2, the amphetamine feels more artificial bodily wise. However ingesting about 500mg caffeine has the similar bodily feel as 10mg amphetamine. Given the amphetamine did some tricks like time delayed whereas the caffeine did not, does make it harder to compare. The caffeine did stay just as long, and provided a much longer bodily high.
These days, I just drink coffee and stay away from pills and powder. Safer.