My experience has not been good with agencies. Part of the problem is that I am trying to alter career paths, and although I believe I have good experience and knowledge, you get pigeon holed by agencies into only being able to do what your past positions have been. Its rare to find a good agent that will spend time on you, i.e. its CICO (CV-in, CV-out and give the money please.......My best experiences have been with my own network of contacts.
