Jay, you and I have discussed the problematic 18 at Oakland Hills-South.
It is a Par 5 for the members. A converted Par 4 for majors. By itself, that means nothing to me. There are probably more great Par 4.5's than Par 5's in the world. (ANGC #13, versus HTGL #15, for example.)
The problem with 18 at OHCC (or maybe it was intended) is that instead of the racetrack-like curve of the fairway at ANGC #13, banked to help a well-struck ball, the 18th fairway at OHCC sort cants in the wrong direction. I seem to remember Tom Doak (I think?) make that observation. I do think that OHCC 18 presents a unique challenge and that it really is a par 4 that is a 4.5, which is psychologically much different than a Par 5 that is a 4.5. You could call it anything, and it would still be what it is. I think that if it were a 5, and we had lots of players shooting for birdies and eagles, it would somehow be psychologically more thrilling than the struggle for pars and bogeys.
The green at OHCC 18 is a wonder of a setting (they recently tore down the old halfway shack behind it) and a superb, original Ross green.