I really enjoy this comic. I remember that, years ago, this was the first comic book that I ever read. Maybe I'm placing some nostalgia on the comic, but I don't think so.
The comic is so rich with DC lore. Even though it is a Superman comic, the arc touches on so much: Brainiac, the New Gods, War World, Maxima, Supergirl, Draaga, and many well known and lesser known comic book heroes. Now that I knw so much more about the DC multiverse, I am still amazed at how well this comic fits together!
However, after the Panic in the Sky arc, there are other follow-on comics that touch on some of the aftermath of Brainiac's attack. Most of them are not very good, but some versions of this story even include a later comic with the famous To Kill a Mockingbird quote from Superman, which is so important in the later Death and Return of Superman storyline.