So there are many Passionate opinions about Ben Affleck as Batman, first off lets look at this Objectively. Ben has had a history of flop movies Paycheck, Daredevil, Runner Runner. Ben has also had an outstanding history of lets say WINS... Argo, The Town, State Of Play, Good Will Hunting... And so on. He's a Good Actor, Seriously.
Let's also look at the FACT that a very large part of his career has been in movies with or directed by Kevin Smith (Batman Aficionado). And to most people that means nothing, but in fact it means a lot. You don't appear in a Kevin Smith movie if you don't like Batman, and your not best friends with him either if you don't like Batman. So therefore he must at least like The Character he's portraying.
We also know that Zack Snyder is a very visual director (Also a Brilliant one) and he wouldn't have been okay with just anyone playing the role of Batman. We thus far determine that he is confident that Ben will uphold the Standard of being possibly the best Superhero of all time. And we also determine that this Caped Crusader is going to be visually pleasing.
I HAVE NO IDEA IF THE MOVIE IS GOING TO BE GREAT, HOWEVER I DO KNOW THAT BEN AFFLECK HAS A HISTORY OF SURPRISING US.
They said Heath Ledger was a poor choice for the Joker