I'd give it an 7-8/10
Really enjoyed part 1 through 4. Liked how characters were being introduced. Story was nicely paced imo. Some scenes weren't necessary while others could've been cut short. Nothing too bad.
Two things I didn't like and that was Diana over doing it with the last terrorist. She was fast enough to block all bullets, I think she could have incapacitated him before he could reload. The other was Martian Manhunter's reveal. Ruined a nice moment between Lois and Martha.
Didn't like part 5. Superman should've come back from the dead by himself and cause more of a surprise. It would also remove Superman vs the League. Diana's lasso should have been enough to defuse the situation anyway.
Part 6 was alright. I'm all for Superman being the strongest but not to the point where it makes Diana and Arthur look useless.
Epilogue. Some nice closure to some of the characters' arc. Set up future movies like Aquaman and I guess Batman v Deathstroke which only the former came to be. Knightmare scene, give me more Mera and I'll take it. It wasn't needed but whatever. And Martian Manhunter should have revealed himself to Clark.