Bob,  You have to find the happy medium about how you feel about the product.  Some things that you are obviously more passionate about, the more you freely write.  I do think that as Laurie says, it depends on the product also.  Larger items have more details and features and sometimes you need to mention those in your review in order for the consumer to have a clue as to what they are buying or looking for.  As long as the bases are covered with a good description of the product and what it does (or is supposed to do) and your personal experience using it should give the consumer all the information that need to make a decision on purchasing or not purchasing an item. 

I see Jo's point also but I don't think that is what you were really referring to in your topic.  I consider one, two, three liners just viewpoints--not a true review.--Karen