Pros
Insight made it really easy to reach out to companies that I would not have otherwise considered as potential employers, which isn't necessarily uncharacteristic of a staffing agency, but the way in which they probed to discover what kinds of positions I would excel at was first class. It never felt transactional, as some agencies can make you feel, instead Insight's recruiters are friendly and open individuals who seem to desire to genuinely place you in a field in which you can be successful.
Kontras
The only con that I can speak to was an issue I had with a potential employer. Insight set up three consecutive interviews for a company that I was interested in working for and when they finally offered me the position and we agreed on a start-date, I didn't hear from them again until a week before my new job was to begin. The news was that the contract had fallen through and I was without a job. Fortunately, a new and better opportunity presented itself and it was Insight's quick work that made my new job transition flawless. That "con" quickly turned around.