Part 2 remains Superman-centered, although Hawkgirl gets a few good moments sending Darkseid flying with a surprise attack and cutting loose Wolverine-style on the Brainiac robots. Superman beats up Darkseid, there's a lot of emphasis on his backstory (when he was brainwashed into conquering Earth), and his feelings for revenge pretty much drive the story.
If there's a problem with the story, it's that the focus is too much on Superman. For one thing, both Brainiac and Darkseid are Superman villains and the fight is over Superman - as in last year's "War World" the rest of the JL doesn't seem to have much to do. That's not necessarily a bad thing, given how Superman was diminished last year. Still, there's room for more of Supe's fellow Justice Leaguers.
Also, New Genesis gets shortchanged here - the Orion/Darkseid thing goes by pretty quick and Mr. Miracle and Forever People are reduced to cameos. This episode might have benefited from a third part - it doesn't look like we'll be seeing the New Gods again this season so a little more detail would have been nice. The bit with the whole Forager/bug/underclass thing seems abruptly tacked on and only barely connects at the end with the idea of orphans brought up 40 minutes earlier (if you get to watch both parts back-to-back).
In fact, part 2 tends to lose the epic feel and seeing the money spent up on screen - we only really get stalwarts Corey Burton and Michael Ironside. Most of the battle takes place in a big room with Brainiac robot-clones. It's just not quite as impressive as part 1.
It also seems as if Superman is...well, kinda brutal here - not particularly heroic. This gives us a major epic battle, but he never really overcomes his rage and it takes Batman to pull him off - at the end Superman still feels he was "right," presumably. Sure, Darkseid's a threat, has killed millions, and will undoubtedly show up again down the road. But he basically brought Superman down to his level here, and Superman doesn't seem to have realized it. File this one under "unresolved issues" - hopefully they'll cover this in the future, since Darkseid may or may not be showing up later in the season.
Overall, part 2 just managed to retain the strengths of part 1, and it's generally satisfactory, but it is somewhat of a letdown from part 1.