Hi Flopter, I own a 150M, and have considered the SIDs. They are not mandatory in Canada, but upon review, I find that my normal inspections and work over the years, have covered nearly all of the SID items. To be honest, the SIDs hit the nail on the head, for what I know the weak areas of the 150 to be. I don't feel that a well maintained Cessna is excessively burdened by the SID inspections. It's Cessna's reaction to the issue of aging aircraft, which no one though would ever last this long, and were not designed to. If they had not done this work, it is certain that the FAA would have mandated something which could have been even more burdensome.