You have contact with one person throughout who helps you get the jobs you want/prefer. I liked this because it created a sense of continuity even though I was sent to different jobs. I could also have honest conversations about the pay and when I asked about potential pay rise I was given an explanation about their policy and when this could be expected.
Cons
My contact person changed after a few months and didn't have the same report with her as with the former one which was a shame.