Pat,
I love this feature as well and it's a design element that really needs a course that plays firm and fast to take advantage of it.
The best example that I've seen of it is at the Kingsley Club. It is both extremely fun and frustrating to watch balls that are miss-hit catch a contour on the green or fairway and collect down into a bunker.
The margin for error on some shots is very small if you take the aggressive approach, as it should be. During my last round at Kingsley, I was playing #13 (the short par 4) and the hole was cut just over the front right bunker. With my approach, I hoped to use a ridge about 20 feet behind and to the left of the hole to feed it down. I hit my approach about 2 feet too far and it stayed on the ridge. I then proceeded to hit my putt into the bunker. I played a bad shot and was penalized, I went from a possible birdie to a quick double!
Here are a few pics at Kingsley that show some collection areas into bunkers:
#2, if short, left or right, your ball will feed into a bunker or down the hill to the right.
#3, the rolls in the fairway magnify misplaced tee shots and feed them into bunkers or the rough. You can also somewhat see the bunker just short of the green that is a magnet for golf balls.
#8, short par 4, approaches pulled or short will collect into the left greenside bunker.
#16, redan par 3 where any slightly pulled approach finds it's way into this bunker.