isn't it all about risk management? we fly with mdds because the type allows for some of those for a prescribed time, thereby minimising risk. being rust buckets as they are, there are way too many of these mdds that continue up to months before anything is done about them.
the allowable prescribed time frame is abused and extended by loopholes, ignorance, laziness, whatever, time and time again and the normal redundancies of these aircrafts that make them REALLY safe becomes eroded by gf engineering's way of doing things and many other reasons.
of course, some mdds increase the load on pilots, possibly to the point that if an event took place coupled with other pressures, they would be overwhelmed.
so please, if anyone thinks these planes are safer than newer machines, explain yourself.