Reviews maybe useful for bugs and horrible checkpoints. If a review talks endlessly about bugs that don't allow you to finish a mission. Checkpoints that are horribly setup. Those types of things hurt a game and the experience. Reviews point that out, yeah it's helpful
However most reviews are just opinions. Did they like the graphics? Did they like the soundtrack? Did they like the characters? Whatnot. Reviews don't help me in those areas.
I played the MP Beta. Played the SP Demo. I know the franchise and what to expect gameplay wise.
Sessler didn't like the Bro's before Hoe's trophy. And there was a part that was too hard and he had to get a friend to beat it for him. Doesn't mean anything to me
However Sessler also said that sometimes the camera pulls back too far in certain parts of the game and you lose track of Kratos. Seen that happen in the demo.
Certain things are fact, others opinion/personal taste.