I thought I would throw my two cents on this subject since I played Greywalls earlier this year (end of May) and actually joined their national membership program after my first round.
I thought the review was complementary until the rating, which I have to say did not justify the quality of the course.
Having played at some of the best public and private golf courses in the U.S. (well mostly Michigan, Illinois, Florida, North Carolina, South Carolina and Virginia) I have to say that Greywalls is in my top 10 and there is no doubt in my mind (having played 11 of Golf Digests top 100 public according to the latest edition) that it is a top 100 public course in the U.S.
I think of any course I've ever played that it is the most difficult to try and "put a number" to how good it is. Mostly in part because it is unlike any course I've played and somewhat because it needs a few years to mature and really take shape. #15, for example, a par 3 is a great hole and needs some maturity for the rock walls along the back of the green, that do seem a little to contrived to take shape (but I've seen some pics of the same hole with grass and moss overlaying these areas on this hole during the summer months and it looked much better). I think the routing was fantastic and each hole has a different feel, my favorite being actually #11, #12 & #13 which have no "greywalls" on them at all (although #18 I am not thrilled about the approach but I'll give it another try before I pass judgement).
The thing I liked most about the course was that you felt as though you weren't playing a course in Michigan or in the United States. I kept telling my playing buddies that I thought I was in some Scandinavian country with the way the trees, rock outcropings and hills meshed together.
The use of the granite rock outcroppings complemented the design and did not trump the quality of the design, placement of bunkers and the greens (which I loved). The course is a great course without the greywalls and I really felt that Mike did a great job of not letting these design elements put too much of a "wow" factor into the course that can take away from the quality of golf that you tend to run into like at an Arcadia Bluffs or Bay Harbor. I felt the holes were very fare, when there was a long par 4, your landing area was very large (#12 honestly felt like a double fairway at a links course) when the hole was short, accuracy was demanded.
Overall I think it was deserving of a higher rating (one that seemed more in-line with the raters comments). I think it is one of those courses that you honestly have to play a few times in order to pass judgement.
I have some great pictures but am unsure on how to actually post them (unless someone can tell me how).