More of a 3.5, but I recognize that that's because of nostalgia. When these comics first came out, I actually didn't regularly read DC comics yet. This was just at the start of my foray into reading DC at all. And, admittedly, the Grant Morrison run of JLA from the late 90s to early 2000s will always remain "my" JLA.
I miss Kyle Rayner and his regular banter with the other core seven so much.
This actual plot is nothing amazing. And the constant ape puns, and quotes and movie references, are a little on the nose. Still, it was nice to finally go back and read an "event" that I had read the first issue of back in the 90s, and then never actually got around to finishing before.