johnM
i think you are missing the whole point here! In days past yes pilots used ADF/NDB in anger and had no fancy GPS displays. even I can remember when I thought it was a luxury being able to move a VOR/DME artificially onto your track instead of getting cross cuts from VOR to VOR or even NDBs to give you a fix. They were far better pilots because they had to think on the hoof with minimal equipment instead of hitting on the autopilot pressing nav and getting the aircraft to fly fancy displays which do and show everything for you.
Of course NDBs have limitations and you would not want to use them for anything but a confirmation of your GPS but what happens if one day your super Gizmo equipt television set panelled aircraft is not available and you end up flying a basic 1980 aircraft with almost original equipment? (yes they do exist) Fly that in anger in solid IMC and yes you will be a good pilot rather than an aeroplane driver
its when everything goes pear shaped that such experience will serve you well!
pace