BvS was pretty lame, but I haven't seen JL yet. Get the feeling it's going to be more of the same (or lame)
It's actually not as dark as BvS. The humor is better. But Batman was better in BvS. It wasn;t bad... It would have been better if they didn;t chop up Zack Snyder's vision of it... I'd recommend watching it... As far as superhero movies go, nothing beats Logan...
I do like the idea of Joss Whedon doing the JL. He did really well with the first Avengers movie.