R. Aharon Lichtenstein, in a recent Commentator interview with Ben Eleff, on the problem of being overly positive or overly negative in a review (link [no ads]):
Lashon ha-rah is one means of undermining a person's career, but there so many other things, problematic aspects to it. The institution of journalism has regarded itself - defined itself -as the watchdogs of the public arena. If you want to be a judge or a watchdog, you are by definition assuming a certain mantle on the one hand. On the other hand, then you should feel yourself subject to strictures such as fairness and objectivity. You may be very unfair not just by writing negative things, but by writing positive things, as well. A person could be an am ha-aretz and be described him as being a gaon olam. If you flatter a person, the issur of chanufah can be the flip side of lashon ha-rah. Chazal in Sotah had very stern things to say about chanufah...See also this column by Dr. Asher Meir: link
Click here to read moreWe don't have a serious tradition of criticism in much of our Jewish world. In certain areas you could very easily say that it is more important not to embarrass this person than to be concerned. For example, maybe people will buy a sefer which is not at all what the reviewer says it is. In very many instances, with many journalists that you read, someone will have written a poor sefer, and the reviewer won't say it's a poor sefer. They say: "Well, this person is a fine talmid chacham, he has six children he needs to support." It becomes a mitzvah rabah to buy this sefer! This enables flooding the market, the Torah market, with second or third grade quality goods - something we can ill-afford.