Is two reeeaaally better than one?

I'm about to fulfill my social resume as an author - soon enough, I will be joining a RP co-blog where a group of crazy, maniacal, distinctly-different teenagers group together to role play in a story, one chapter at a time.
It'll be a bla--mUAUAHahhauUauah--
Eh.
I am trying to decide if I want to role play a ninja or an assassin (they're essentially the same thing), and one of my closest friends was saying a vampire might be thrown in.  My brother is going to be a mythical creature called a Dkhotoan (think slate blue, wings, and super agile), and I think we may have some elves/queens.  Oh boyo.  x)
Until then, I thought I would go ahead and mark out the pros and cons of co-writing versus solo-writing:

CO-WRITING
Pros:
   -You don't have to deal with the nitty-gritty of an outline.  Whereas I would get stuck on one idea if I was soloing a story, my fellow author is always there to help me get out of seemingly inescapable plot holes.  As they say - two heads are better than one!
   -Insta-editor!  Just add coffee, generous compliments, and humility.
   -Half the actual writing!  Unless...if you decide to double a normal story's length and each write the length of one story...  ;)
   -Insta-anti-writer's-block!  If you ever hit writer's block, you always have your partner there to bug his/her eyes at you and say, "Why haven't you been writing?  Hm?  Hmhm?  Hmhmhmmm?!"
   -Quality time.  Personally, this is my favorite part of co-writing.  I've only co-written twice, and neither books are finished (though one will be).  Odd as it is, however, I don't mind that I have a half-finished story rotting in the empty corners of my computer.  I learned and am learning a lot about my writing partners; long chats about outlines, plot holes, plot, plot, plot, redoing plot, reworking plot, refilling plot, totally trashing plot, starting plot all over, and PLOT have taught me several skills about communication, empathy, and sincerity.
Cons:
   -Your partner is bound to annoy you.  This ties in with the last point of the above; if you have a writing-partner who agrees with your every word, I'd like to see your cloning machine.
   -Writing is slooow.  You have to agree on a final outline, you have to agree on characters' ages, expressions, and looks, you have to agree on the characters you each will be writing.  That's a TON more red-tape than there is in solo-writing.

SOLO-WRITING
Pros:
   -All decisions are up to you.  If you notice a loophole, you just find the most convenient way to close it.  If a character is inconsistent, you just rewrite as you wish.  If you are sitting down to deal with logistics like time of year, daytime, ages, and other numbers, you don't have to run everything by someone else.
   -You have more control over the characters.  They are your children, and you can make them do whatever horrors that you so desire.
   -You follow your own time schedule.  Frequently in co-writing, you make an outline, your partner finishes the first chapter, and then it's your turn; the pressure of someone standing behind you, waiting for you to finish so that he/she can begin the third chapter is nonexistent in solo-writing.
   -Nobody has to know what you're writing or all the flaws you make in the writing process.  For example, I think the people who got DWBSN after I had taken out Drew (a snooty character who belonged in a first-grade girls' book, not a romance novel) think I'm way better of an author than those who got the version of DWBSN with Drew in it.  We make silly mistakes like adding unnecessary characters and events, and when you write alone, you can make as many silly mistakes as you want, and no one will know.  Not so in co-writing.
Cons:
   -Solo-writing can be rather lonely at times.  When you first stare at a blank document or sheet of paper and take a deep sigh, you can see exactly how everything will transfer from your outline to the story, but it's still hard to take up a pen and write your first words.  (That's what I've been told, anyway...I personally love starting stories.)  At other times, your characters are being jerks, and they refuse to do what you want them to do.  Unlike with co-writing where you have someone else to team up with you against your creations, you're all...alone...
   -You make ten-thousand times more mistakes.  There have been countless times when I've mentioned a seemingly flawless plot idea to Josh (my brother and co-author), and he's deconstructed it and showed me all the flaws.  While that process is painful, it saves a BOATLOAD of rewriting.
   -When you're done with the story, no one else is there to celebrate with you.  You kind of just sit there, stare at the screen, scroll through all 100 pages or so, then do a happy dance in your seat and squeal a little maybe, but that's it.  Very anti-climactic, I found.

Hehehe, so there you have it!  I'll try to get you some material from the co-written story I'm doing (since we officially started writing), plus more of my solo-written story, and if I get permission, I'll also send out the link for the RP co-blog that me and my peeps are doing.

Write on!
Clove