Aterpester,
I understand and agree that Precision approach aids are more precise than visual aids such as papis
If one flies an ILS,the glide slope is the most accurate but Papis should be monitored as well,as they give an easier,less precise guidance than the glide slope at low altitudes.(it was mentioned earlier,that new pilots may find easier to follow the papis in the last 500 feet than the glide)..
If one flies a VNAV app,the papis should also be included in the scan for cross checking(distance versus altitude).
If one flies a Visual, the Papis provide the best guidance when turning final.
If one flies a non precision app (Vor,Ndb),the papis provide the best guidance until distance to threshold is such that the aiming point is clearly identified and followed.
Also, the Papis position (left or right or runway) should always be briefed(especially during non prec.app)as they will give an additional clue that you are aligned with the correct runway.
Knowing if the papis for the runway you will use are calibrated for 747 will give you an extra clue as whether to follow them precisely until approaching the threshold or if an earlier transition to the aiming point is more adequate.
I hope that clarifies my previous posts and general idea on the subject
