Have used a sample of this. My serving size consisted of just 2 scoops. I was only be getting 2/3rds of the recommended dosage so had to factor this into my final review.
Much like the original Jack3d it recommends scooping up to 3 scoops, which equates to a whopping 390mg of Caffeine. Honestly if you are relying on just caffeine to take you back to the DMAA headspace, you are doing it wrong.
Taste 8/10: for 2 scoops it tasted pretty strong, little wonder why it requires so much water, especially at 3 scoops. Quite a nice pineapple taste.
I gunned it back and waited about 30 mins before starting my workout. I felt quite stimulated, and focused. By the time I started lifting, I felt good, but only really comparable to most other preworkouts these days. Some beta alanine tingles, though not over powering.
I'd say 1 hour after drinking, the energy was dissipating. The stand out for me however was the pump in my triceps and chest.
I liked it, but did it bring anything new to the table? No. The recommended dosage is 3 scoops, and I only had 2, which seemed adequate. But even at 2 scoops per workout that's just over 22 workouts. If tolerance builds, you'd be looking at 3 scoops, so even less. Gutt3d.