Wreck was useless.
Wreck should be done as a separate course with a qualified (I don't mean certified to teach) instructor.
S&R is really a great class, hence I don't like doing it for AOW, but a separate class. I've been thinking about for the 5th dive I require DSMB (others PPB, nav, night, deep). I'm ordering the instructor guide as I want to see if it would be a good fit. While I teach my students to deploy a DSMB from depth in OW, I think more stringent performance requirements (I have yet to see the performance requirements) may make that useful adventure dive, as a student should be able to do a slow ascent, keeping the line tight. That is an important skill to have in my opinion.