I really enjoyed this issue.
I still prefer Waid's Supergirl Joe Kelly's or even Lobe's. It's like nobody thought to give Kara a personality. The whole concept seems to be "she's Superman's cousin! Isn't that great!" Waid gives Kara the same personality he gave her in Legion, a vapid valley girl, but I still prefer it.
While I'm at it, Hal's been great these past two issues. Of course, my only long-term exposer to Hal is Waid's previous Brave and the Bold mini and JLA: Year One.
The plot is simple:
Find "The Book of Destiny," a book that knows all history. The book knows past, present, and future 'history.' The thief has taken to Ventura, a planet revolving entirely around gambling. Meanwhile, Batman is trying to get the weapon from issue one back to Gotham. Blue Beetle shows up because alien tech makes his suit jumpy. At the end of the issue, someone with a more sinister bent gets "The Book of Destiny." This guy wants to use it to destroy the Thanagarian race. GL manages to grab the Zeta beam with the racist bigot, but Supergirl is left behind. Next issue is Batman and The Blue Beetle.
A plot like this leaves lots a room for character interaction, and lots of busy panels. Really that's the strength of the book, watching the superheroes interact. Last issue, we saw Batman and Green Lantern take turns playing to their strength. This issue we saw old-guard Green Lantern playing against new-guard Supergirl. One thing that gets mentioned early on is that GL has a secret identity, but Supergirl does not. That pretty much sums-up their differences, if you ask me.