I've used their Bing Search add-in and find that very good. Unlike the standard Bing search you can configure yourself, it puts the results on a separate page (The simple Bing version has them in a drop down box which then navigates away from your site).
One issue with it is that you can't use it as it is on ASPX pages or with ASPX Masterpages. If anyone wants to know how to do this I can put together a 'how-to'.