Compare
What each of them treats as the truth
The useful question is not which tool writes tests faster. It is what each one treats as the record of what your product does.
Test generators
The record is the test file. Delete the tests and you have lost the description of the product. Coverage is whatever someone remembered to record.
Developer portals
The record is the service catalogue — teams, repos, ownership. It knows what you run. It does not know what it does.
Browsing agents
The record is a session. Excellent at finding a bug once; nothing persists that can tell you what a change will reach next month.
featkpr
The record is the map, built from your code, docs and release notes. Tests hang off it. Delete every test and the description of the product survives.
Named, dated, sourced comparisons against specific products are being written, each with its evidence file. They are not published yet, and we would rather show nothing than show a claim about someone else's product that we have not checked this month.
Want this on your product?
We are building the first version with a handful of teams. Tell us what you test with and what breaks.