This is especially the case with Pathfinder.
While, yes, I do have the Dungeon Master's Guide and all of the NPCs contained within, I'm not that flash on the rules behind feats and powers so if I want to do it credit I really need to either craft the NPCs myself or re-read all of the feats and powers before game. Unfortunately, the players are kind of in that in-between stage CR-wise so there wasn't going to be too many choices of credible NPC threats within it anyway.
That's one of the benefits of running World of Darkness or Call of Cthulhu games. You can handwavium it a fair bit. It's the rare Storyteller who has a portfolio of NPCs and an even rarer one that frequently refers to them. Oftentimes its just a case of guessing what they might probably have.
Since Pathfinder is, by necessity, a more mathematical game where feats and equipment and racial abilities and attributes all affect even the simplest and most necessary statistics (attack, damage, armor class), then you can't just guesstimate it. This is doubly so because the Pathfinder enemies are more likely to be out to kill the player characters than the average WoD enemy.
So I'm going to space out my prep-work over this week so I'm ready for next session. I have an Inquisitor and some wannabe pirates to write up as well as a cleric they've been meaning to assassinate. Then I also need to update the new World of Darkness conversion rules for Demon: the Fallen for the upcoming campaign.
I think that's my problem. I run A LOT of games and if I'm distracted by other projects - such as my Horrors on the Home Front supplement - than I can find myself fast running out of time.
Oh well, it shouldn't be too often an issue for the Flashpoint campaign now that I have the major plot considerations tucked away.