Let me begin by saying by saying that I am a huge fan of Jeph Loeb and Ed McGuinness' run on Superman/Batman, and the six issue public enemies arch is one of my favorite team ups of all time. Needless to say I have been anticipating this movie all summer and I have to say that although it's not the best DC animated project out there that it's definitely worth the watch.
Before watching the movie I decided that refresher was needed and so I diligently reread the comics, and as the movie unfolded I was amazed at how good the adaption was. Just about every character and every plot element from the comics have made their ways into the picture, the adaption even goes so far to include much of the dialogue from the panels of the book. I'm not sure I've seen an adaptation of anything come as close to the source as Public Enemies has. In fact, I'll go as far to say that what diversions they made were actual improvements to the story rather than glaring errors(which is usual outcome when writers veer from the source).
In Loeb original story Metallo just kind of shows up without any real setup, other than to provide Batman with a little intrigue.On top of that the logic that Luthor uses to set up the need for his bounty on the caped crusaders is so far out fetched that it's kind of tough to believe the world would rally against their favorite protectors like. So instead of towing the line the dirctor here chose to incorporate Metalo's attack with a frame job that puts Superman with odds with the government which is a much more believable set up than Loeb's original. Also on the sidelines are the world's finest extended families(robin, night wing and the whole super family). While they had a purpose in the comic they would only provide confusion to the average viewer of the movie who i only familiar with the Bruce Timm's adventures of Batman and Superman and the Justic league.
Speaking of the Timm animated universe, this is where Public Enemies falls short. While the two previous DC features follow the hitherto unseen origins of Wonder Woman and the Green Lantern, Public Enemies follows two heroes whom we've already known on a mission that we've more or less already seen on Justice League Unlimited. While the story and action are great it feels less like a movie and more like a couple of good episodes of the Justice League that have been pasted together. So while it's certainly better than Superman: Doomsday, which murdered its source material, it falls short of previous films like Wonder Woman merely because we've already seen the relationship between Superman and Batman develop in Justice League and the original animated pairing World's Finest.
However, that short coming aside it's a great watch, so great that after watching it online I purchased it on amazon, so I guess you know where I stand.