As much as online user reviews can be hit or miss, I particularly like the way they're being implemented on Steam. Most importantly, before you can write a review, you must have first launched that game from Steam -- and your playtime will be shown next to your evaluation.
Don't get me wrong, I'm still expecting a bunch of garbage, but if I can find value in community guides, there's hope that user reviews will be beneficial as well. This system, currently in beta, is taking over Steam's user recommendations which can now be made visible to the public by going to your Reviews page should you have written any before.
While Valve is considering creating an overall score based on player ratings, that's not yet in place. That might be for the best.
via destructoid http://www.destructoid.com/steam-introduces-user-reviews-266406.phtml