I am leaning towards thinking that green contours and fall aways may really be the thing to focus on.
I think so too.
Flattening greens so as to speed them up is like throwing elite players into the briar patch. Fast greens may scare hackers or perhaps someone with the yips but good love fast greens. And making them flat just lets them make more putts.
Brent,
Its not just the flattening, but the typical back to front slope to assist holding shots. If the green was at all firm, there would be some interplay and tradeoff to a flatter green - they would need more spin on flatter greens, less spin on steeper ones.
The double tier green on 15 seemed to give them some trouble, with short shots spinning backwards several yards from the hole. Of course, I saw Tiger practicing his "dead hands low spin" swing and he had no trouble.
I think a variety of slopes on front to back greens - some nearly flat, some up to 3% or more, some greens or areas of greens having reverse or side slopes only, and some fall aways that roll a missed shot away from the hole, like 15, or off the greens like Pinehurst, would be what was necessary to make green shots challenging for pros. That might lead to more members three putts, but those are usually less painful than losing balls in trees and hitting in bunkers.