Looking For Recommendation on API

Hi all. I am looking for recommendations (for or against) for a tool that will help us manage our PPC keywords, bids, campaigns, etc. We are advertising on the top 4 (Google, Yahoo, MSN, and Ask) and are probably going to add Looksmart into the mix soon. As you can imagine, it's getting tough to manage these accounts by logging into the individual engines. I was approached by Channel Advisor and I've read a little about their Search Advisor product. Does anyone use this tool and, if so, what are your thoughts about it (good or bad)? Do you use another product and, if so, can you tell me a little about that one?

Thanks in advance.

-Shari