Thanks for the comment! Really helped to show that I’m thinking in the right direction. I’m playing around with the tags now as well. I’m not a fan of the tag cloud widget, but I can set up a Page with links to the permalinked tags for quick search results to the most recent reviews in those tags/categories.
Even if I have to maintain a manual list on a separate page, It would be cool to have a sortable functionality similar to an excel list. Each product listed in the first column, with the other categories in columns to the right, also sortable. Then each product clickable in the first column to go directly to that product’s review. Not automated and driven by the new Posts, but functional.