[BEWARE OF *SPOILERS* BELOW!]
Thanks for Batman-News, we may have just gotten a little insight into what Ben Affleck's Bruce Wayne may be like. According to the site, they've got the scoop on one of the man's hobbies- and it's one that seems pretty fitting to the character.
Bruce likes himself some MMA.
Their anonymous source claims that a scene was recently shot in a place that was turned into a mock-underground MMA arena. It evoked thoughts of Fight Club, and included a large crowd of men placing bets, as underground brawlers duke it out center stage. Wayne apparently shows up, which causes a bit of a stir as the onlookers are surprised to see a billionaire alone in this dark, violent, seedy place. As he places a bet and goes to the bar, he nonchalantly explains to a stunned patron, "I'm kind of a night person."
This sounds about right. It definitely stands in contrast to Christian Bale's more reclusive Bruce Wayne. It sounds like Affleck's version of the character won't be scared to mix it up with the locals, and will attempt to blend in from time to time- perhaps to keep his ear to the ground.