So, there is already a truncated thread regarding the importance of review scores here on this page. Some people are arguing that scores don't matter. Others are saying that it is foolish to spend $60 without some sort of insight into the quality of the game.
I would never argue with someone else preferences on the matter, but I will speak to my personal experience.
I have been a gamer almost all my life. I'm always open to new experiences, but at the same time I do have a fairly good idea of the kinds of games I enjoy, and the kinds of games I don't enjoy.
Out of all the games I've purchased in the past 3 years, the only ones that have disappointed me are the ones I purchased purely because of positive reviews. Games like Vanquish, LA Noire, Dead Space 2.... all great games, but just not for me. The thing is, I was never excited about these titles. I only bought them because of how excited other people were about them.
All of my favorite games (the ones I still play constantly) were day-1 purchases. Games like Halo Reach, Mass Effect 2, Bad Company 2, Assassin's Creed Brotherhood.... I never bothered to read any reviews for these titles.
I personally feel that we get so much comprehensive preview coverage that I can tell if a game will be enjoyable for me or not, long before the reviews are released.