These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Author's Saving Throw: The announcement that Booster Gold and Ted Kord's Blue Beetle will be joining the book, and that it takes place not in Prime Earth but a variation on New Earth, has been met with high praise in comparison to the Darker and Edgier tone that has been given to the book to that point.
Being announced shortly after the cancellation of the Legion of Super-Heroes, lead to complaints that DC were cancelling the book so they could relaunch it with the Justice League branding.
Whilst the announcement that the creative team behind Justice League International would be reuniting for the book was well received, Kevin Maguire's subsequent departure and Howard Porter taking over art duties before the first issue had even been released because DC wanted a grittier book drew some ire. The subsequent three month delay of the series' launch so Porter could redraw Maguire's issues didn't help matters.
Epileptic Trees: From the moment the character designs were unveiled, fans began speculating that Wonder Woman and the Flash were the absent-since-Flashpoint Donna Troy and Wally West purely because the Flash had red hair and green eyes, two of Wally's distinctive characteristics.
Replacement Scrappy: How many Legion fans view the team and the entire book, replacing a long running team with a multitude of characterization, storylines, and more than a few POC and LGBT characters in its roster, for another Justice League knock-off title during a time when DC is becoming over-saturated with them.
What an Idiot: Superman refuses to listen to the fact that he can't fly now, despite the Wonder Twins, the other members of the Justice League, and personal experience telling him so.