It's how some people are interpreting it that makes it a mess. Their interpretation is that Johns, Berg and Nelson fucked Snyder over and the fans of what has been done in the DCEU thus far feel alienated because they're making changes. Usual fanboy bullshit.
I think you should watch The Room first before going to something like this. I don't think you would have as good of an experience if you just jumped into the deep end.
Watched it yesterday. It was alright. The first hour dragged like a motherfucker to me. The last hour was pretty good tho. Elton John stole the movie. Wasn't near on the level the first film was, but I could stand for Vaughn doing one more if he would tighten it up a bit.
Regardless of what happens, the JL thread will be a mess. If the movie flops critically and/or under-performs, the DC fans will lose their minds. If the movie does well critically and/or makes a lot money, people will prod those same fanboys into acting like idiots. It's a lose-lose situation.