Add me to another who really enjoyed it. Loved it as a nod to the era. We had a thread and reviews for it a while back, I guess the forums don't go that far back anymore?
It worked for me visually and thematically as a prequel to Kingdom Come, as this was somewhat the world and heroes they had lost to a more dark cynical modern era.
There is a visual mirroring or flipping of a scene in KC which retroactively foreshadows, a parallel scene in Justice.
(my interpretation anyway)
The clash between Luthor and Braniac was great, as those two on the same team, you had to expect, they would be trying to deceive one-another to their own ends.
The heroes, and the way they were each taken out, all somewhat spoke to their character and history.
Particularly Barry Allen and Hal Jordan, who at the time were not allowed to "exist" in the actual DCU.
If I remember correctly there was also a companion book with quick origins of all the characters? Or was that part of the Treasury sized Ross/Dini books? I feel like it ties into Justice though, as that was the era they were celebrating.