It's good to have Ryan Choi and Ray Terrill back in continuity. That's exactly the sort of thing that Rebirth should be doing. But this collection of intro stories for the new JLA isn't particularly notably. They're mostly forgettable origins, with the exception of the Killer Frost story, which is a strong continuation of her story in the Suicide Squad and a great character piece. 
 I'm looking forward to the new JLA, and this is a nice setup for it, but as with any "Secret Origins" volume, it's regurgitating already-told stories (or at the least variations on a theme), and there's only so far you can go with that.