Note that these are still stimulants tho. Vyvanse is unique in that its a slightly modified dextroamphetamine (adderall) molecule that gradually gets metabolized by the liver into dextroamphetamine, sort of a "natural" extended release and has a much smoother (side) effect curve. Concerts and XR are just cleverly designed pills that release two doses of plain methylphenidate/amphetamine spaced out, so there's two distinct peaks with a small lull between.

Yes, that's correct. The slow release makes a big difference for a lot of people compared to traditional Adderall/Ritalin