John Stewart fans only like him, because he's an African American and nothing else.
Most would say that Diana is an immortal that existed for thousands of years and just as old as the amazons in pre-flashpoint. Which isn't true, because the Amazons were given a specific task to guard dooms doorway that requires something that's beyond a human mortality to await gifts from the Gods. Diana wasn't created for that task. She's been stated to be a mortal multiple times among other characters such as Aries in Greg Rucka's run.
Superman is a flawless overpowered superhero that has never dealt with personal struggles.
Kyle Rayner's ring is more powerful than an ordinary power ring. Which isn't true. It only had advantages, but doesn't mean it's more powerful than a regular power ring.
The Grayson run is overrated. I guess readers didn't expect the series to receive impressive sales, given the fact that Dick is in a new identity other than Nightwing. So I guess it was a risk.