As far as mixability, taste, and rate of inducement, Jack3d certainly rates a 5, overall though, I have to rate it 4/5.
Dosing with only 1 scoop produced absolutely no noticeable changes in energy, pump, vascularity, strength or focus.
Dosing with 2 scoops produced increased energy, though I would feel a noticeable decline in said energy within 20 mins of onset of workout.
Jack3d appeard to have no effect on either pump or vascularity with 2 scoops.
Focus is usually strong, so again, no noticeable changes with 2 scoops.
Strength has increased greatly, but due to the inclusion on further USPLabs supplements (such as Test Powder, Prime, Compound 20 ), I can neither credit nor discredit Jack3d for this increase.
As far as any "crashing", I often feel extremely tired within 4hrs after my workout, but I don't feel that this is a "crash", but rather a natural affect of the the extreme amount of energy that I expend during my workouts (I prefer high intensity).
Would I use this product again? I'm usually highly resistant to most Pre-Workout Supps, so the fact that I could see any kind of increase in energy (however short-lived), and without Stims to boot, I'd have to say yes, I will use this product again.