I have been using Amino Energy for months now. I use for a pre-workout and its replaced any type of energy drink and even the need to stop and get a coffee. I love the taste of Fruit Fusion. No shakes - I am just ready to workout/run/work/study whatever I need to get done. I have not experienced a crash a result of taking. Only reason I am giving it a four star rating is because I wish it could be more intense but still a very good source of energy.
I have the Watermelon flavor. Tastes great, mixes well, does what it says! The caffeine here comes from green tea, which is awesome, and the aminos help with muscle repair and hydration. I agree with some of the reviewers that the energy high doesn't last as long as with other preworkouts, but for me that's actually sort of a benefit because it means you can drink coffee or something later in the day without feeling like you're having a heart attack. Great value for the money. I'll definitely buy again and try other flavors too.
This review is specific to Amino Energy, Watermelon