No, adderall is absolutely not like cocaine in the body. Different substances completely. Stop watching television. There's little truth to be found there.
The biggest problem I personally have with it is the racemic amphetamine mixture in adderall causes excessive PNS stimulation. It kills my workouts. One-hundred milligrams of ephedrine is nothing to me, either, but the addys are too overstimulating. If you find this problem, I would suggest looking into dexedrine, which contains only the pure dextroamphetamine salt. You will get the nervous system effects without the PNS overstimulation (or, at least, much less so).
Stimulants definitely have powerful metabolic effects in vivo. Appetite suppression can vary -- I find very little myself, but many can't eat much on it. Increased heart rate and nervous system stimulation can hinder muscle growth.
I suggest using sparingly and as prescribed by your doctor or psych. If you start snorting several points a day, bad things will happen. Not that you want to snort grams of binders into your nasal passages anyway...
HTH