only tried a few but they all produced good results. no explode is the product i chose to go with after sampling no vapor, black powder and explode. the pump and energy are amazing. opinions are mixed about long term results, however it gives an extra rep or two every time. i have had some strength gains and the thought of leaving the gym doesnt even cross my mind, i finish what i started every time.
its the stim that does it, not the NO. i took a new stim and had a great workout as i didnt want to leave the gym. thats how the manufacturer convinces you its the No when its really a heavy dose of caffeine.