This SID discussion is going round and round ... I had a review recently on more then a dozen of them and was shocked by the results - most of the owners paid extraordinary amounts of cash for them and did receive only checked lists as a result - no pictures, no videos, no real documentation. I then started to visit the maintenance organizations and check photos and docs on what they really did. First of all, almost everybody got ripped off by the companies. Many bills were mere street robbery and many, many people did not get half of what they paid for. What was presented as finding, was often poorly documented and where it was, it was quite often obviously unnecessary work done. Yes, the Cessna corrosion inspection is a good thing to do and in some few cases there were really potential things to stop, but the most of these findings are covered by ADs already. I also had the inspection done on my plane (Reims built) and as a result I am quite happy to know the plane is fine and free of corrosion, but we also had some preventive corrosion treatment to not have a problem in 10 years - fine with me and worth the money I spent, but that was about one third of the typical inspection costs charged. So people, do the Cessna corrosion inspection, but stay close when they do it, because even your old buddy workshop will try to rip you off.