Some purchase this stack so they always have versatility in their options. On a typical day Prolific may be their go-to. Another day, maybe they already drank a coffee or energy drink, or they are working out late at night, or are just doing cardio...High Volume is the go-to for any time they want to avoid caffeine but still get the pump and performance edge.
Scoop for scoop Prolific and High Volume deliver similarly in terms of pump and performance. However, sometimes people are looking to get double the pump and performance, plus the energy and focus. Rather than going for 2 scoops of Prolific, which is a lot of caffeine for most, you can instead go 1 scoop of both Prolific and High Volume. Just mix them right in your cup at the same time!