The category is broader than most buyers think
Some products called document review tools are really OCR tools, extraction APIs, enterprise search products, or workflow systems with a document module. That is why buyers often get confused in early evaluations. They are comparing tools that sound similar but support very different working styles.
Reviewers need evidence, not just outputs
A document review product becomes useful when a reviewer can move from a question to a verified answer quickly. If the tool produces an output but still forces someone to re-open the source and hunt for proof manually, it has not really improved the workflow.
The safest buying lens is workflow fit
The simplest way to compare document review tools is to map the product to one real review motion. If it helps that workflow run faster without weakening evidence quality, it is worth the shortlist. If it only looks good in a feature demo, it is probably the wrong tool.