There are lots of people telling others to write reviews without having purchased/used a product. Did you have to do it too? I mean, is your site only side by side comparisons or do you also post reviews?
My site does not have any reviews. Each product overview is just a description of the product and its specifications. Rather than telling people which one to buy I give them the ability to find the one that best fits their criteria. I rank all of the products by how popular they are and I think many people trust this more than they do a review.