Reviews matter, and and I wish there were more of them. John Cooper is by far my favorite, and I also like trancejeremy's and MerricB's reviews quite a bit.
I agree that the star system is not terribly useful. I think it needs to be finer-grained (half-stars, perhaps), and there is indeed quite a bit of grade inflation (which I may be guilty of myself), particularly for the older reviews. Three-star reviews really ought to be a lot more prevalent, so that the truly exceptional stuff is more visible. I'd be interested in scavenging some older 3.0 material from bargain bins now and then, but in a lot of cases, the reviews are uniformly tiny and four-starred. It's not a lot to go on.