Certain STDs do have their uses. (Synthetic Training Devices, I mean!). Expensive full-motion simulators are used for the majority of flight training on large aircraft and PC-based emulators can be very useful for understanding how instruments etc. respond in procedural flying and for practising FMS interactivity.
The full-motion simulators which I instruct upon are no longer realistic of the aircraft they purport to represent and my first flight in the real aircraft with new students is invariably taken up with teaching the differences in handling (much heavier in roll and a totally different stick force gradient in pitch), plus the vastly different avionic fit. Although it is quite fun to beat up the aerodrome at 20 ft and 350KIAS in the 'box' now and again!
Things like MS Flight Simulator give an unrealistic idea of HOW to fly an aircraft, but they do at least give their players (not 'pilots') an idea of WHAT the instruments represent as aircraft attitude and instrument indications can be seen at the same time. They are virtually useless for anything else - but understanding the progress of, for example, an NDB join, hold and let down by being able to watch both flight path and instrument response simultaneously is a most worthwhile training aid. Anything more is just an expensive substitute for the boyhood game of sitting on an old chair with a broomstick pretending to be a fighter pilot!!