What I have noticed with RH since I first started interviewing with them is that they are incredibly interested in your last three supervisors. They are more interested in obtaining their information that during the many calls, they forget why they initially called you.
Their behavior suggests that they are interested more in getting their candidates within the company people submit to them so they can solicit more staffing business. I dont know anyone who has ever worked for them that I have met in person or I have never met anyone at any location that worked for them as a consultant or a contractor.
I have asked them to keep me off their call list.