OK465:
Once you seen a few of these unusually intricate RNP AR approaches (MHTG, ZUNZ, KPSP, PAJN, 'Red Dog', etc.) you gain a high degree of comfort and confidence in this capability.
They are fantastic. Trouble is, few will ever be able to play in that sand box because the bar is set very high.
And, you mention PAJN. Only the home-plate airline gets to fly that one. I can have the best equipped RNP AR airplane going and Alaska Airlines in concert with the FAA has locked me out of Alaska Airline's "little part of the world." The state of Alaska shamefully has only one public RNP AR approach procedure. The remainder (and there are quite a few) are preferential special (private) procedures that exist to help a monopoly airline.