If I used a particular product and it worked well for me and its dyno proven, it will be posted up here with good reviews. But why wouldn't I post up a negative review if the product sucked you asked?
Well the answer is simple, there are just too many products that doesn't work and if I were to post all of them up here it will be a never ending task.
Besides, this blog is never about product reviews in the first place. It is about documenting the products and modifications that are relevant to the turbo project.