I feel like I am fairly knowledgeble about stimulants and I have a resentment bias against vyvanse. One reason is it was marketed as the "once a day" med for adhd by SHIRE who also makes adderall. They did that coincidentally when adderall went generic. It never lasts the purported 12 hours and most people I know get 8 out of it. The way it is metabolized is through the gut so eating something of substance gets the digestive juices going which helps it get going. Its heavily pushed and marketed and magically they just received a patent renewal so it wont be generic yet in the USA. HOWEVER there is a generic of it in the UK. Hmmmmm...