i have used the drug Modafinil....it's an RC mostly made for airline pilots to cope with less sleep. i felt waaaay more cognatively aware when i was on it, and incredibly didn't really need sleep for a day with no crash after.
it made me feel a waay bigger cognative boost than adderall ever has, if i was still in school and needed to cram i would swear by it. but being an adult i really have no use for it in day to day life. it was a crazy thing to experience the time i did it, though. i wouldn't have believed such a drug existed without a huge crash at the end or feeling droopy the whole time.
edit: i don't recommend anyone take this or any other RC. i've taken a lot of them bc i'm a moron though.