I brought this digitally, I bring that up because while searching the index for Booster titles I was surprised to see they have the first few issues of Extreme Justice. If I ever feel brave enough to see the legendary bad art it might make for entertaining read. Might, I'm not sure if EJ is a "so bad it's good" read or a "why did I get this?" read. Anyway...
Robinson can write some truly bad stories and he can do some amazing memorable tales too. I got the first two volumes of Starman and while I enjoyed it I do think the dialogue could be distractingly off. I only read through this once and nothing really stuck out at me except perhaps the Trinitys' narration boxes and constantly referring to superheroes as Wonders. Nothing that took me out of the story like Starman tended to do from time to time. The Trinity, Supergirl and Robin all come off as heroic. Their deaths are heartbreaking especially Bruces' goodbye to Helena which has him acting like a real dad, not the jackass he's usually acting like in the main books to all his sons. It does raise the question of what he expected his daughter to do since he didn't inform her of his impending death until it was too late. Perhaps Robinson assumed her mother was still alive since her fate would be revealed much later in Worlds' Finest #0. Regardless this kind of makes Bruce look like a poor parent and planner in hindsight.
I do think Diana comes off a little too stereotypical outside her talk with Mercury. She's mainly thinking of killing the enemy. Yes she wants revenge for the deaths of her fellow Amazons and her gods but she seems more concerned will taking life than protecting the innocents. Superman is kind of a mess and out of the three has the least amount of focus during the final battle. It's still a moving opening but I think it would have made more of an impact if Wonder Woman and Superman were more centered on the mission it's self. I suppose it's a counterpoint to each other with WW with vengeance on her mind, Superman grieving and Batman only thinking of the plan. It just irks me.
The change in Alan Scott has gotten some attention and the only problem I could have with it is the potential of not having his kids. But that's something the reboot of the character already took away. He's likable and pretty much how I remember him despite being younger. His lover Sam isn't fleshed out too much but it would have been the same whether he was a woman or a man. Yes his death is cliché but at the same time I do like the symbolism with the engagement ring becoming the power ring. There's a lot of things being set up like the question if there were others who wielded the power before Alan that aren't answered. I don't know if these questions ever will be answered since Robinson left and that worries me a bit. I know other writers have different ideas that don't always mesh, sometimes the new ideas work and sometimes they really don't.
Hawkgirl and Atom are pretty interesting individually and together, there's history there but all we know for sure is that they used to work together. I'm guessing there was a romance between them in the past before she went AWOL which would be cool to explore. I'm guessing that outside the Trinitys' past romances (Lois/Clark, Selina/Bruce and maybe Diana/Steve) not many will be explored since the relaunch is trying to do new things. Like for example Jay Garrick and his now ex-girlfriend Joan. I think the treatment of Joans' character is the worst thing in this trade. She's just cold and Jay never comes off as truly deserving it. At worst he doesn't take her choice to start a new life seriously and has no idea what to do with his life. Jay isn't a bad person just not sure of his future. Making Joan act like he was just a fun weekend but now something nasty she stepped in isn't a take I'm fond of. It feels like the most insulting way possible to say "forget all the couples you liked because we're not doing that." There are easier ways to do that like having Jay realize he missed his chance to get together with her since she's with another guy. Something like that which doesn't make her like mean for the sake of making Jay look better.
Even without that scene I'd already like Jay, he is by far the character that's the most fun to read. He's the one that's totally out of his depths, eager to help, to make something out of himself and already hero worships the others. Jay is the fanboy, likely the youngest hero (not sure how old Kendra is) and the most optimistic. I truly enjoyed the twist of Mercury giving him the speed powers (with Mercury having that iconic hat) and I'm fond of the costume too.
Grundy was never a character I cared for one way or another but I can actually see him as a threat here. The danger in great and I like the world that's being built. There are flaws sure, I just think the positives--at present--outweigh the negatives. This is FAR better than Worlds' Finest and I'm looking forward to seeing where this goes.