So this thread is a few days old, but to add my experiences, I've spoken with two "talent" agencies, one that specializes in design and another that tries to specialize in technical people. Design is easy because it's subjective, but even to the common eye there's a difference between good and bad and how those relate to their client's brand. The problem with the latter is that they were focused on past job titles because they didn't actually understand the industries they were working with enough to be able to say "Okay well this guy can write in X, which translates well to Y, and has a strong interest in Z." In doing a little more research, there were a few companies that did seem to know their stuff, but they weren't in my area. If you find one, do a little bit more research about them as individuals and as a company to see if they can actually help you or if you'll just land in a database full of people who maximized buzzwords on their resumes.