One thing I've learned about pre workout supps is everyone reacts differently. I started with Cellucor's M5 for a while, but the effects wore off after about a year of cycling off and on. SuperPump 250 went well for awhile with some great pumps and energy gains. After a couple tries of JP8, all it gave me were some rough ass backpumps and felt like I was gonna puke throughout my workout. Jack3d, I had an allergic reaction and flipped out everytime I tried it.
I've been using NO Shotgun for the last 4 weeks with good energy, pumps and a noticeable strength gain. Plus, I'm not all jittery after a dose and can focus well when I'm training.