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
thruuu
Very deep SERP and AI-source research.
thruuu analyzes up to 100 Google results and extracts headings, topics, questions, on-page data and AI citations: https://thruuu.com/serp-analysis-tool