I was finally able to get around to watching episode 12 and I think I'll just have to describe my reactions throughout:
Mild spoilers for those who haven't seen it yet.
In the first part, D.C. Confidential, when it first started I was thinking, "OH JOY, a RECAP episode." Then the not-so-subtly implied yuri WINcest at the end made up for it.
Part 2, Panty + Brief, was actually pretty damn good. When it seemed like Panty and Stocking both were going to return to Heaven, I was kinda bummed out, "Why do they have to go?" Then Panty was left behind, I kind of understand the reasoning behind it. She was doing a half-assed job of killing ghosts and mainly focused on fucking, thus the reason for the sex ban.
Though we don't actually see it on screen, we also learn that Brief can kick some ghost ass on his own, as his coming back after Panty dropped him off with those ghosts would imply. At the party, when Panty was looking through the aquarium and saw Brief I was thinking, "NO FUCKING WAY?! Is that who I think it is?" Also it was funny to see Garterbelt cock-blocking every man Panty tried to get with at the party.
Then once the action started up with Scanty & Kneesocks, I was kind of hoping that Stocking would come back with the cavalry from Heaven but Brief saved the day. Brief is now officially bad-ass in my book. After they had to hide the burn-downed building and Panty said she would "settle for [Brief] as [her] 1000th" to paraphrase, the fanboy in me turned into a "squeeing fangirl" but once the episode came to an end on one hell of a cliffhanger I was like "............ What the fuck?!?!?!?! DAMN YOU GAINAX!!!!!"