Know everything. Cons: You aren't surprised with anything. Pros: You can advance through the game much quicker than everyone else.
Perhaps, maybe it's only me that likes progressing in games as a totally new experience, I learn enough about a game to where I learn if it's worth obtaining, then after that, I learn no more. I like progressing slowly as a noob for my first time, and love the surprises.
But I see your point.