After some overwhelming responses of "Your sample size isn't big enough" blah blah blah, I've decided to keep track of everything I purchase from here on out and get more.
UPDATE: I have spent about 5M more credits since this post and have updated results - click here to see them! Ok, I promised to do a little experiment to.
From personal experience, I believe a Regular Spectre Pack wins, hands down! The only time you should even think about buying a Premium Spectre Pack (PSP) is if you've just.