I followed the development of the drug when it was Kempharm before they changed their name to Zevra, and from what I remember it lasts a lot longer, like 14 hours, which is what I remember the main difference being compared to other drugs like Adderall
I don't know much more except it doesn't appear to have been selling a lot because the company that owns it only had $2.9M revenue last quarter reported, but expects to report over $11M revenue on March 28th for the most recent quarter (Oct 1st - Dec 31st), so maybe it's becoming more popular to be prescribed for whatever reasons like more effective, more profitable to prescribe, etc