Patrick,
I agree with TD on making long par 4 greens smaller and better defended. Hitting them with a wedge vs a long iron seems to favor or at least equalize the hole for shorter hitters. Granted, with more bunkers or whatever, they could possibly top one in there. It just illustrates the theory of the architects dilema - bad shots or exceptionally good ones can ruin any theory temporarily, but if we take a big enough sample size of shots, eventually it should work out as intended.
And, as I noted, its possible to extend the LZ to create different challenges, using narrower fw, rumpled fw, grass bunkers, and even the occaisional sand bunker for a staggered visual effect in lesser used areas of the fw.
Sean,
I disagree on cross bunkers be efficient. Thinking of something similar to the Principles Nose at TOC, whereever you place them, they challenge just one particular carry length. If 275/245/215/195/145 from the various tees, anyone who drives well past that has no issue.
Angled bunkers, extending some length, in combo with multiple tees have potential to challenge a whole range of tee shots similarly.