I'm a little bit worried about Arkham Knight. I loved Arkham Asylum. Arkham City was great too. Arkham Origins didn't bring anything new to the table though. And in retrospect Asylum and City were quite similar too. Why would Arkham Knight be any different?
Knight is more similar to City than Asylum. There's nothing that groundbreaking in the game, aside from the transforming batmobile/tank thing. Overall, if you enjoyed City/Asylum you'll likely enjoy Knight as well. The game looks gorgeous as well.