Well, on Amazon, from personal experience, half a star difference means a BIG difference in quality. So, unless the product has a suspiciously low number of sales, I'll go for 5 stars. Price is also important to analyze on Amazon. If it has a low price and a huge number of reviews, I'll know those reviews do not reflect high quality, but rather a quality corresponding to the low price. Again, since I'm looking for high quality, I'll go for 5 stars, even (or maybe: because) it costs more.