Trust some of the reviews, but keep in mind that someone is more likely to write a spiteful review if their product is broken than they are to write a good review if their product is working.
That's why many motherboard reviews have ~ 60% 4 and 5 egg reviews and ~ 30% 1 egg reviews.
I would ignore any review that says "THIS PRODUCT WAS DOA DO NOT BUY IT!!!!" because the place you bought it from will likely replace it right away. I would trust professional sites like Anandtech.com as well.
I generally just take the reviews with a grain of salt. Make sure you read the review instead of just looking at the rating. Some of them are well done and have good reasoning. A lot of the 1 eggs are people who just got one that was doa, which happens with almost any part.