Larry, I maintain a website called
www.conquestowners.org and one of our primary goals is stopping Cessna SIDS. On the 441's they cost around $100,000 per plane. It did not make the airplane any safer, they did not find any "smoking gun" hiding in the airframe, it did nothing for owners of the aircraft but cost money, devalue the airplanes, and take away 6 weeks of down time. There are a few legal groups kicking around the idea of a class action lawsuit against Cessna for creating SIDs, but from what we learned through the FAA is SID's are not mandatory. They carry no more weight of enforcement than a Service Bulletin.
I would like to discuss the SID issue more, so that owners of 337's are not taken advantage of by Cessna service centers and having to buy loads of Cessna parts. The 441 SID program caused a one year sales spike of $14,000,000 dollars of part sales for Cessna that otherwise would not have taken place. They love SIDs, it's thier way of making money off old airplanes. And it is thier hope that they can remove some old airplanes off the market so that you buy new airplanes. Or they want to make old airplanes so expensive to own, future buyers opt for the factory new model.
Rumor has it that the early Citation 500's are in line for it next, as are 421s.
-Jason