Man I love this stuff! I've tried it a couple times now and am really impressed.
It definitely gives you a solid boost in energy and focus before you start training but what I really noticed is that it doesn't over do it. Sometimes you take stuff like that and it makes you jittery and weird for a short period of time and then there is a huge crash.
I get up at 4:45 every wednsday to drive 2hrs (one way) down to Columbus for training. It's a struggle to get out of the car and wake up and be ready to train as hard as we need to. This stuff really kicks me into drive for max effort bench.