Personally, I've always had a love-hate relationship with Adderall. I took it for several months in 2009 in order to finish my novel, but the long affair with the drug, combined with my insomnia, turned me into a zombie for the duration. To this day there's still a lot of days I spent 12+ hour Adderall-induced shifts writing that are a total blur to me. I'll reread chapters I wrote, and for the most part the quality is only slightly watered down to where it would be if I had written it sober (a task which only allows for me to write about 2-3 hours a day if I really push myself). However, there's still a lot of the writing that I will read three times over before asking myself, "what was I thinking when I wrote this?"
But that's the idea - you aren't really thinking. Taking Adderall when you do not have ADD/ADHD turns you into a productivity machine, and your individuality suffers. For this reason I believe Adderall to be better used when trying to lay the groundwork for a project - I'm sure Kerouac didn't submit that 120 foot long paragraph to his editors without plenty of sober editing, after all (or at least as sober as Kerouac could manage). The process also seems ideal for anyone stuck in a dead-end 9 to 5 office job. If the CEOs of big business could convince the proper authorities to let them pump Adderall into all of their employees in the aforementioned unfortunate position, they would have themselves an army of endlessly productive super servants. For that reason alone I think it's a blessing that Adderall is a prescription-only drug. That, and the fact that staying up for days on end completely shot out hasn't done any favors for anyone I've ever met.