Well it is fairly evident from logs, partial or not partial, that Outlaw keeps up just fine and often outperforms the other 2 specs.
he "sometimes" play WoW because he is a Diablo player mostly, I believe. Point is that he ran a bunch 3-chested 11s with 3 Outlaw rogues on DPS the other day, which would be a great example of 3 good Outlaw rogues - That would change your experience with Outlaw rogues, so that next time someone asks you you would have something else to share =x
I also went in and clicked some of top logs on various dungeons/levels, and none of them appear incomplete or partial - they all have a duration to the very right, quite clearly indicating that, so I guess you got unlucky.