Have been using JP8 for a couple of weeks now. In the past, I have used other pre-workout supplements like SuperPump, NO Shotgun, etc. and I must say that I am really impressed with JP8.
I take it about 45 minutes before my workout as that seems to be the time frame in which it starts working. In my opinion, this has been a great addition to my workout. The energy is consistent and sustained, while not at all overstimulating. Really, this product does what it is that I would expect from a pre-workout supplement, and it does it very well.
The only drawback, as others have mentioned before, is the taste. It can be a bit tough to get down at first if you try it with just water. I started mixing it with juice (V8 splash or blueberry/acai juice) and that has helped tremendously. Seems to be a quality product at a reasonable price and there is no doubt that I will continue to use it.