If "best hole I've seen" can be loosely translated as "hole I'd be A-OK with playing for the rest of my life, or they can bury my ashes there", then I'd be put my name on the list with Mr.Engh with regard to #15 at CPC.
Is #16 better, no. One-dimensional hole, that becomes less interesting as you get older and are unable to make the carry.
Is #9 better, no (but really close). The combination of #8 and #9 is an incredible set of Par4s. But the risk-reward of #9 would eventually become a drive & pitch as you get older.
But the setting, challenge and peacefulness of #15 is unmatched. You could spend an hour on the hole, and maybe only hit two tee-shots, and it would be a great hour spent. It tests your accuracy, your short-game, your putting, your ability to concentrate despite the setting, and your ability to be one with nature and appreciate that certain places in the world are perfect.