SC may well be wrong about the ANO and the use of GPS, but surely he gives sensible advice in the rest of his post. Does anyone here disagree?
I've not flown with a certified GNS430/530 whatever so can't comment with any authority whatsoever upon them, but do they not rely on databases of published instrument approaches? If so, then presumably terrain clearance is assured by the published procedure, and not by a terrain database on the GPS. Feel free to correct if my understanding is incorrect however.
I fly with a BK Skymap III complete with terrain and obstruction data
. I am perfectly happy to rely on it for range/bearing to next waypoint/nearest airport etc, but would never rely on it for terrain clearance. If that's considered a backwards view by some then fair enough.