Research depth
Discovery
How well the tool supports keyword, competitor, SERP, backlink, or market research before execution.
Scalenut
Deep SERP, competitor, topic, prompt, and page-level research is documented, though the site does not document every possible data source.
The Features FAQ says SERP statistics come from the top 30 ranking articles and Cruise Mode breaks down the top 10/20/30 competitor outlines: https://www.scalenut.com/features
SEOTesting
Broad first-party reporting and experiment research over Search Console data, including page/query, comparison, content decay, cannibalization and group analysis.
The product lists Search Console exports, page/query detail and comparison reports at https://seotesting.com/google-search-console-data/ and content groups at https://seotesting.com/features/.