I have taken vinpocetine quite a bit although it has been a while. It has been around for a quite a while. It comes from the vinca minor plant which I have also grown as a ground cover. Dark green foliage with beautiful blue flowers and can be grown in full shade and can handle a harsh winter, but maybe I digress but what the hey.
There is a pile of studies on pubmed which confirm its ability to increase blood flow in the brain. As with many supplements and prescription drugs it is the impact over a period of months that should be measured. Having said that, many herbs do have immediate impact as well. Depending on what else is in your stack, vinpocetine can cross-potentiate a bit so that you can get wired if you don't adjust what else you are taking. Particularly if you are a coffee drinker. Same thing with taking fisetin - which I have not done- but am pretty sure that it would cross-potentiate with coq10 if one is already taking that or with pqq and so on. Not saying that is bad because it could be good. Just that there would be a difference between taking fisetin standalone versus in combination.
Huperzine-A needs to be cycled as I recall or else it causes some kind of shutdown in some feedback loop. I can't recall but I think it is like a five days on- five days off type of thing. So personally I would not want it in a formula with other things if I wanted to take the other things everyday. I dont think huperzine and vinpocetine are all that expensive but somehow when supplement sellers combine things it is supposed to be new and wondrous and it may be but you can still see what is in the formula and reverse engineer it to just get the components separately and in the dosage you want rather than the pittance in the combo formulas.
With huperzine and vinpocitine you are beginning to edge over into the world of nootropics- which I am not saying is a bad thing. Next comes the cetams. paracetam, anaracetam, oxycetam, lucidril, noopept, bacopa, phosphatydalserine, and so on. Google is your friend.