In 2007 we had a buyer purchasing a home on the Southwest side of Ann Arbor near Dicken elementary school. The home was built in early 60's when Orangeburg pipe was very common so we recommended that they have a sewer line inspection.
(All buyer agents should be recommending this but I'm guessing many designated buyer agents don't because they don't have the experience to know. This is an example of a typical difference and why many larger brokerages hide behind designated buyer agency.)
Michigan law requires that designated buyers agents disclose in writing that they are designated not full buyer agents. However most agents seemed to be afraid to tell buyers they are just designated buyer agents.
For information on Orangeburg: http://www.sewerhistory.org/grfx/components/pipe-orng1.htm
This home was a foreclosure. However we were still able to negotiate a price reduction because of the failing sewer line.