"... Make no mistake - the course is tough. 75.6/149 from the back and 74.0/145 from the member tees ..."
I was actually fairly surprised to read these numbers. At 6930 from the back, and 6510 from the front tees, these handicap and slope numbers seem a little high to me. I've played The Dunes a fair number of times, and never really considered it that tough a course. The fairways are pretty generous, and most of the greens are not that difficult to get at once you figure out the right angles. The par 3's require what could be called "heroic" shots, but the greens are pretty big on those holes. I think once you've been around the course a few times, and figure out where to leave driver in the bag, like 3 and 7, and where to lay up to on the par 5's, scoring shouldn't be that hard. 9 is real tough.
For comparison, Olympia Fields from the tips at 7,205, has a course rating of 75.9 and slope of 147, member tees are 6,605, rating of 73.2 and slope 140. In my opinion, Olympia Fields North is a far more difficult course, both for the scratch and bogey player.
Is OFCC North under-rated for difficulty or Dunes rated overly difficult? I think probably a little of both.