As a result of some of the earlier comments here, I would say that the autopilot systems only improve efficiency, not safety.
I believe hand flying a departure or an approach is no less safe than any auto system.
Also, I remember when the pilots managed their time so that the pilot flying the approach would have some suitable short time for some 'rest' prior to the descent/approach, to partially offset the effects of 'the 14 hour day'..
...and don't think for a minute that I haven't been there!
Cheers.....
