One upon a time the only way you could get a product review was through a print rag or through an analyst firm. James pointed me at this review of Sun vs. Dell. This is an end-user giving a pretty technical view of performance and the like.
Reviews like this are all part of the participatory movement - they differ from the conventional recommendation found on Amazon in that they are far more authentic and detailed. In some respects the person doing the review is passing their intellectual property back into the community.