I've worked with paid take home tests for a while, but stopped again. Hiring managers started to make the assignments more convoluted, i.e. stopped respecting the candidate's time. Candidates, on the flip side, always said they don't want to bother with the bureaucracy of writing an invoice and reporting it for their taxes etc., so didn't want to be paid.
Now my logic is: If a take home test is designed to take more than two hours, we need to redesign it. Two hours of interviews, two hours of take home test, that ought to suffice.
If we're still unsure after that, I sometimes offered the candidate a time limited freelance position, paid obviously. We've ended up hiring everyone who went into that process though.