To be blunt, I can only see JL going three ways.
Simplistic and satisfying. (300/DoTD-MAYBE MOS)
Ambitious and divisive-(Watchmen..and MOS to an extent)
I guess when push comes to shove I'd want the second one for JL. Because Avengers ate Justice League's lunch in terms of creating a simplistic series of events with good character moments.
Though I think I'll be arguing about that movie with all my film buddies
Which would give it an edge over Avengers. The most people argue is whether Loki was a strong enough villain or not