Its no secret anymore that the official shooting script leaked, so i've googled a bit for feedback (Not the actual script as i don't want to read it anyway) and came across this site:
www.scriptgirl.net
She read the script and loved it, this is what she had to say on her Twitter page:
Just read the new Predators script. despite being demographically unsuitable, I loved the damn thing. Full of surprises and carnage. McTiernan-ites will be pleased.
Brody's actually perfect. his role is not what you expect, way better than all that AvP dreck.
So that would be another positive feedback for the script.