I worked for them as an Account Manager at one time! They were great to work with back then when we had several accounts together under our umbrella of responsibility but there was never anything really bad that came up during my tenure so it's not something i can comment about negatively or positively from personal experience.
Maybe just because this was such long ago now (5 years) - however their services are still very much available today if you're looking into hiring outside agencies/companies etc., which may be beneficial depending upon your needs & budget constraints? As mentioned above though, nothing comes across negative here either way. We used other companies over the past few months before deciding between 2 others due to cost reasons.