Mmmm. No3x is a bit like C4. Better for someone who isn't used to stims. When you start needing 2-3 scoops to get a kick you know it's time to change.
Plus at this point, you're having nearly 450mg of caffeine. There's plenty of other stims that can give the same effect with less risk to your heart. Not saying they're better because I've never researched that. But too much caffeine gives me jitters and anxiety.
Srs though, if you want a serious workout DMAA is one way. But some people get some really bad crashes. And people blame it for other health problems.
There is a few stimulants out there that can offer similar effects.
L-Tyrosine, a larger dose 2g+ is excellent for extra concentration and a bit of energy. ALCAR is similar.
There's been mention of AMP Citrate as well. DMBA could be used also. Phenylpiracetam. Synephrine. Phenylethylamine. Hordenine. Methyltytamine. Theobromine.
I'm not saying any of these are better for you than caffeine or DMAA. But they can be used to the same effect.