It's more 11b than Need. I admit that there are parts of both that are pretty much impossible, and I can't blame them on the other author. The lube inside the condom in 11b? That was my dumb-ass fault. On the other hand, maybe there are people who like that (I just think it would be really hard to keep the condom from falling off...)
Okay, that's actually all I have to say about co-writing: it's hard not to be in total control. I know, I'm having all sorts of amazing revelations this week.
About those fics specifically? For those who care:
11b--- I was beyond bored and emailed the very chatty m-mslash list and asked if someone wanted to co-write something with me. Jericho answered. Yes, that's the whole story. We went back and forth on Yahoo!Messenger, each writing a couple of paragraghs. She did Lindsey's POV in third person. I did Xander's. You can tell who did what at the beginning, but after that the lines are a little blurred.
Need--- I wrote the first part and liked it and was proud of it and all that, but put the fic aside to continue later. This was right before season 6/3 started, and when I went back to the fic, I discovered that I still can't write Angel for shit, but grinny, daddy!Angel, crush!Angel? I have no idea who he is, can't write him. I posted the first part and asked if anyone would be interested in doing a round robin sort of deal. And author I really like answered, and we sort of lazily wrote five more parts between us. She did the Angel POV in third person, I did the Xander (notice a pattern?), each of our parts was about a page and a half. She's listed as anonymous because she's retired now, but I'm still forwarding feedback whether she wants it or not. Why do all the authors I really like quit writing or switch to Smallville fic? Why do toilets flush counter-clockwise? These are the great mysteries of the universe.