I've been using this preworkout powder only a couple weeks, but long enough to provide some initial feedback. First, the company that makes it seems very professional. They have answered questions I sent them quickly and honestly.
Regarding the product itself, I mix it with warm water 30 - 45 mins before workout. The warm water helps the powder dissolve quickly. But it tastes horrible. Too sweet, and you can only dilute it so much before you can't drink any more. Part of the bad taste might be the ingredients themselves, not the sweetener. In any case, I just tell myself that it tastes bad like strong medicine and drink it down.
It does seem to help keep my energy up during workout. But not a lot, it doesn't contain any of the common stimulants like caffeine, but enough to keep me going during my evening workouts. I can feel the tingle in my body of the Beta-Alanine. I freaked out the first time I felt this, but then read it's a normal response to this supplement. You know what I mean if you've taken it yourself.
The biggest benefit I've noticed is not during my workout, but in the days following my workout. One or more of the ingredients of this powder prevents the muscle stiffness and soreness that I normally feel. This benefit alone makes it worthwhile.
Hope this helps someone else.