most pres these days, especially the amp ones are all basically the same and pretty mediocre. only one that stands out is nutraclipse alphadrive.
it has a very clean centrally stimulating feeling.
for guys who use non-stim products like high volume but want a bit of energy, a combination of caffeine, dlpa and chocamine is actually quite effective. the dlpa reduces pain and improves mood via inhibition of breakdown of enkephalins and the chocamine has certain mood boosting qualities itself, despite only containing minucule amounts of several substances despite caffeine and theobromine, somehow they seem to work together to create a nice slightly serotonergic feel, which is a good addition to the dopaminergic effects of the dlpa. gives a balanced feeling.
people can throw a cap or two of ampitropin in there and some theanine and they will have a good strong clean stim.