I'll state my bias up front. It's very common that once a member posts a review, the WKs and bashers both show up, along with people who just want to piggy back the thread instead of adding complete information in a review of their own. Often as not, a lot of shit gets stirred or at best the water is muddied, not helping people make decisions.
Many members claim to have decided to just stop doing reviews because it isn't worth the hassle. I believe more reviews would get posted (and more information be available thereby) if comments were not allowed. I thought it would be interesting to get a general perspective.