Just finished this one. Pretty good. Not as good as the best Justice League movies like New Frontier and Flashpoint Paradox, but not bad either. Good animation, nice artwork, and plenty of action.
I'm still not sold on Aquaman being cool, but I didn't think he as a complete cheesefest here, either.
One big thing that stuck out, though, was the scene in the final battle when Ocean Master has Aquaman stabbed through, hanging off the end of the Trident. Then after Cyborg plays the footage of Ocean Master's confession to the Atlantean army; sudden Aquaman stands up and gives this big speech like he was never wounded, and there's not a scratch on him. That bothered me.