Pros
Steve Pieczko, the RelMap founder is the #1 pro. We met and worked together on a high profile project for one of my former employers. There was mutual respect. We stayed in touch. Steve negotiated a contract-to-hire position for me with one of his long-standing clients, which he brought to my attention. I was hired at the term of the contract. I am the happiest I have ever been in my career, spanning 20 + years. I owe it all to Steve for recognizing the fit and making the connection.
Cons
No cons from my perspective. While I was a contractor, Steve represented me better than I could have myself. His talent is knowing the market and people and making matches. I tested the water with a half dozen firms prior to reaching out to Steve. None produced results.