I used all kinds of forms of Tyrosine and Tyramine and they do produce the "focus" that's marketed in pre-workouts. Ive tried Huperzine on its own and in ive used pre-workouts that have it. Never noticed much from super zine but so many of the nootropics are useless if you don't combine them with some kind of precursor that makes it more bioavailable.
Ive tried a few of C Bums energy drinks. I don't know the difference. Some come in cans some in plastic bottles, some are stim free, some have close to 400 mgs of caffeine. One pre-workout, Total War, has over 400 mgs of caffeine. In my opinion C Bums energy drinks are average.
I think Huperzine is like yohimbine, overdose it and it's a likely ER visit and a very bad "trip." The Gorilla Mind Lightning contains both; or it's rauwolscine/alpha-yohimbine, but in low doses.
I bought some plain tyrosine and 5 grams noticeably potentiates any stims, Rx or otherwise. That dose is given to cocaine addicts withdrawing to replenish dopamine.
Those caffeine doses don't feel pleasant at all

I never once even felt the caffeine kick of a cup of coffee from a Red Bull or several, or from the million Red Bull copies. Kind of strange, maybe the taurine somehow cancels the caffeine similar to theanine.