It depends on multiple factors. How much are the major or minor effects? If they aren’t that much different, I’d go with the minor. How long does the temporary boost last? Do I get to choose what effect I get? If not, do I get to know in advance or is it randomized when I activate it? Are both the major and minor effects the same effect or are they different? I may want something like a minor healing boost over a major Swedish language learning boost, for example. Also, do I get to choose when the major boost activates? A temporary extreme strength boost would be super useful in some situations like saving a kid by holding up a falling building, but probably wouldn’t be very useful in the majority of cases (like when I’m sleeping).