I'll jump in. I'm sure I'm considered completely biased, even though I shot a career-low round at St. Enodoc, which included a birdie at the 6th, and I'm a huge fan of the course in general. Don't count this as a vote, but I'll make the contrary case.
It is indeed an impressive hill you've got to carry at St. Enodoc, and if that's the only criterion for victory here, then it should win the overall prize. Then again, if the 16th at Old Mac already eliminated the 3rd at Gleneagles, then there must be something more involved, no?
I think the hole at Old Mac should win because of the green and the bunkering around it. St. Enodoc's green is a relatively small target, but clearing the hill is pretty easy unless you've hit a crap tee shot, and there is really nothing to the green, with everything outside the green funneling down unless it gets caught in the rough.
And I think, so far, I'm the only one who's offered an opinion based on actually having played both holes, multiple times to boot!