What good is the BAM WCF Interceptor???

A colleague and I were discussing the difference between BizTalk default BAM interceptors and the WCF/WF BAM interceptors. The question came up as to what specifically can theBAM WCF provide that the default Pipeline interceptors can't.

Well I will first start with the overall purpose. The purpose of the BAM WCF Interceptor is to allow WCF Services and WCF Clients to take advantage of the BAM infrastructure. WCF Services and Clients can update BAM Checkpoints (KPI’s) for an already deployed BAM Activity Definition. It essentially can record the same data as the Receive and Send Ports of the BizTalk BAM Tracking profile. However, there are a few additions to the WCF Interceptors that the Receive and Send Ports cannot accomplish. For example, the WCF interceptor can record Client and Service Faults, Channel Faults and other conditions that can occur within the WCF Channel layer. Also, the WCF Interceptor can use XPath to navigate the message and parameters, to record plethora of aggregated values such as getting a “Sum”, “Avg”, “Min”, “Max”, or “Count” of repeating items. Any valid xpath expression can be used with the only limitation being that if an Xpath returns multiple nodes, only the first node out of the collection is used.