I honestly expected more out of this stuff after reading reviews from people saying they started shaking and running around like a crackhead within 15 minutes of taking this shit. I pounded one of the 8oz RTD's before my workout and didn't really notice a whole lot aside from the jittery caffeine buzz. My heart rate didnt even increase that much. It did give me a decent amount of energy but I'm not a big fan of the jitters. Then again I have a high tolerance for stimulants. Anyone like this stuff?