The best guide to Bing I've seen so far is Microsoft's video about the "decision engine," which gives you a good idea how it works for a targeted set of query types. If your query is not one of those types, of course, it doesn't work as well. However, the query interface seems to be better than Google's, in general. Whether the particular results (ie sites found) are better than Google's is a different matter.
The Behind Bing section of the Discover Bing site includes videos of four of the key players. This is also one site to watch if you want to incorporate Bing's API's in your products