I was reading an interview with Terry Gillam, and came across this quote, which I think totally nailed the problem maybe with Public Enemies.
Because most of the things he's aiming to do... I'm not a great fan of "Public Enemies," because I think he's a fucking extraordinary film maker, but personally I didn't think Johnny had enough room to act. The one scene that was good was where he's in prison, in jail, and Chris is outside. That was the only time I really thought, "Okay, now you've got some room here to do something." And that's what bothered me about it. It didn't allow him enough moments like that. It was just push, push, push. Put that fedora on. Wear the clothing. Because he can be fantastic and I like it when he plays it down, I agree. I just thought there was too much of it where he just was there, but he didn't have the moments to allow him to do just a little bit more. [laughs] He's making so much money.