Swift Learner decisively wins the struggle for the title of most deceptively lousy perk. It may certainly seem like a good investment when you first look at it, but since the xp requirement for each new level rises linearly, even if you get all three slots of Swift Learner you only ever stay a few levels ahead of someone who doesn't ruin their early game wasting invaluable perks. For starters, you have to wait until level 17 before you're even one whole level ahead of the "slow" learner, and if you eventually get to level 30, which should not be until the game is over anyway, you'll still be only two levels ahead. So, that adds up eventually to a few HP and skill points, for three perks... Simply put, do not choose this perk even if it threatens you with a radiated stick.