Public Enemies is not a good movie, even though it ought to be.
Michael Mann has made movies I very much enjoy. He made Heat. Heat is an awesome movie, and it runs parallel to Public Enemies in a number of ways: each had a good cast, plenty of budget, interesting subject matter, and were beautifully shot and edited. Hell, even the costume design was good.

Despite being a Kentucky Colonel, Colonel Depp failed to make anything useful of this film.
Heat, however, was somehow far less ponderous, than Public Enemies. The dialog wasn’t nearly as clunky. The score to Heat was very good, but the music in Public Enemy was a heavy-handed beating.
I wanted to like Public Enemy, but we couldn’t even finish it because it was so boring. It was so boring, my wife started idly studying Arabic and I ended up installing wordpress plugins and making cookies. We skipped to the last chapter, saw that it ended in a moderately historically accurate fashion, and then turned it off.
Also, Universal Studios has terrible Blu-Ray production. Just because my player connects to the Internet doesn’t mean you have to make it do something with that. Also, do you need to advertise for the Blu-Ray format and try to convince me that I need to watch Blu-Rays on a new Blu-Ray player when I am already watching a Blu-Ray?
Score
On the High Five Scale, Public Enemies (Blu-Ray) gets a 2 out of 5.