Just a note for anyone passing by. The side effects are rare, except diarrhea and you need to watch your liver enzyme levels if I remember right. Everyone I know who's taken that had diarrhea the entire time (manageable with meds), and it will screw your liver long term.
I think the GI effects are basically the same between any of the -afinils, FWIW.
I wouldn't recommend them in general, but mostly because they last too long to really work with a normal 16/8 sleep cycle and the other stimmy effects can detract from things other than focus work.
I never took any long-term, but I've actually napped (purposefully) the afternoon after taking one in the morning, which is impossible on amphetamines.
Which is to say, they seem better to me, but maybe long-term use is different.
But I'm not a doctor either so who knows really.