Thing to keep in mind is to decide what speed should be used in the emergency descent. If big bang down the back and no comms from the back either, coupled with obvious massive depressurisation, then assume there is a significant structural danger. Note the IAS at time of depressurisation and don't go faster than that during the descent lest you tear the plane apart if the structure has already been weakened. This means a compromise between getting it down quickly to breathable altitudes while hoping the passenger oxy doesn't run out of puff (like the pun? I did..) and spearing down at high speed hoping it doesn't fall apart on the way. Most simulator sessions accent the high dive policy which is relatively easy when compared with the think it through slow speed descent assuming structural failure somewhere. The latter needs to be practiced as much as the former - but rarely is the case.