Concentric secured a consulting position for me with a company I've wanted to work with. They have relationships with IT managers to find out about jobs that other people don't know about..Positions that aren't on the web. It was a perfect fit. I was a consultant for 8 months and then the company offered me a full time position. Concentric supported me the entire way.
Cons
There was no downside. I would absolutely work with Concentric again and I share my experience with all my networking groups and colleagues.