Public Enemies does a good job of visually taking you back to the look of the 1930's era. The actors do a nice job with what they're given to do.
The weakness here is that this is a very plot-driven movie, with little insight into Dillinger, his gang, or even the dogged FBI agent pursuing him. They also barely mention the ongoing hardships of the Depression of the time, which certainly played a role here in this story.
For die-hard Depp or Bale fans, or fans of the Tommy gun, you'll likely enjoy it anyway.
I went to see this because I am a fan of Segal and Rudd. I thought it was fairly good, but not great. Definitely not as "hilarious" as it's being marketed as. Both actors definitely have better movies ahead of them. Most of the comedy was basically making fun of Rudd's character's awkardness which got old quickly. But both actors are so likable so I stuck with it. The move works best when both actors share scenes. And I did laugh a few times. Go see it if you really like the actors and just ignore the hype and I think you'll will enjoy it.