I'm more for CO, unless DCU is offering something really spectacular. Writing quests is an entirely different animal than writing comics, and I withhold my judgement on Marv and Johns in this arena. We'll see if they're any good at writing half a story for us to finish.
The only thing that's compelling to me about the DCU right now is the GL Mythos. I used to be a big Teen Titans fan, but part of that appeal is being a junior leaguer, and the rest of it is teaming up with a small like-minded group. I don't see that happening so much. "Booster Silver" may never see the light of day.
From what I've seen of DCU, now that I've been enlightened, their customizability has nothing on COs. It's not like they're a little bit behind, and who knows what they might be able to accomplish during Alpha and Beta, but they're not even going that direction. They might have a lot of in-game/loot related development and advancement and diversification, but as far as creation itself, it can't get much more simple: Pick your Power, your Source and your Travel Power. Done.
And their acrobatics run looks ugly, though CO could do with some wall sticking.
Why would this be the most expensive? 30 servers isn't hard for a random guy, its easily done with a giant corporation 10 fold. This idea was first told to us at the San Diego Comic-Con 08, but they changed it somewhere in between now and then.
And it should be hard to get Superman, the early bird gets the worm as they always say. Stuck with Aquaman or the Wondertwins maybe yes, you can't satisfy everyone. Also do you know how many heroes/villains there are in DC, believe me you would not have to make a server for every player.
A system to let players use the main characters of an IP, taking into account some are vastly more popular/powerful/desirable than others is a big, big cookie. First come first serve is absolutely unacceptable. In order for everyone to have a shot, they have to be able to change hands, and to do so fairly. This means they have to be earned, and competed over, and won or rented for some period of time.
The method of gaining Hero Points to rent the big heroes or the method of competing could be anything. Maybe the custom characters have several hundred leaderboards they are measured on, and each hero corresponds to a particular leaderboard accomplishment. Maybe players gain Hero Points along with XP, and can 'save up' for time as Title Hero. Maybe there are missions and/or task forces that act as an additional gateway to access certain characters.
Regardless, such a system is too complicated for the streamlined design they seem to be shooting for.
How anyone sees DCU's graphics as "cartoony" is a bit odd to me.