When I was at an agency we used the Search Advisor platform for managing all the PPC search programs in Google, Yahoo!, MSN, etc. I personally thought the system was awesome and the price was right. We never did use it for shopping engines because at the time we used another vendor who would crawl client sites, upload and manage them for us. For Chanel Advisor I think we had to create the feeds and that wasn't something we wanted to mess with.
If the shopping feed tools and technology are on par with the PPC management system then they should be really good. They've been around for quite a while and probably have as much if not more experience than anyone in the industry.