I'm on Dextroamphetamine for ADHD (basically Adderall, different salts but both are amphetamines) so if you have any questions just ask.
As far as your original question: obviously it's a great precontest drug provided you can still eat enough on it. As someone before me said, you need to make sure you're on a continuous dosing schedule throughout the day because when it wears off too soon, the hunger will come back with a vengeance!
It's probably also not the healthiest thing to do while also on AAS and doing heavy weight training but for me, I'm on a béta-blocker as well so my blood pressure and heart rate can't go high even if I tried (I can't get my heart rate over 90 bpm even if I tried and my bp is always low no matter what). Without something controlling bp and heart rate, it's probably not the safest thing you can do but is it effective? Hell yes! You'll also find you can train harder/more intensely.