Okay, so to be more specific, what I'm looking for is some evidence that isn't purely (and fantastically) anecdotal. Even videos of situations where Aikido may not defeat another martial art or a brawler, but at least holds its own for a long time.
You wont find that kind of evidence about any art. Fights are usually over in less than a minute. Even in a world where everyone carries a video camera no-one could get it out quick enough to record the fight.