Out of the several Rec2Rec agencies I briefed on my requirements, Harrisons are the only one who have consistent sent candidates, one of whom I have hired and others I could well have hired if I needed more people.
The consultants reach out to you about roles that aren't really active or even real, so they can get a message back to then try and sell a worse opportunity. They also lie when they say the initial fake jobs are filled, to avoid being caught falsely advertising to attract interest. Not an appropriate way to handle business and completely unprofessional.