I had the pleasure of playing Sleepy Hollow about three weeks ago. It is a special place and golf course. New Yorkers have it so nice for great golf courses and beautiful neighborhoods.
It's hard to add upon the various comments offered so far, but I'll do my best.
1. Uniqueness - I felt I was playing a course with a unique routing and walk. You make sort of a hook-shaped walk. After an opening hole, you walk steeply up the 2nd hole to a high plateau that sits above and behind the clubhouse. You play holes 3-16 up on this rocky, undulating plateau where many times you can see much of the golf course to be played. The 17th takes you back down to the valley, and the 18th back up to the clubhouse, to complete the walk.
2. Shaping and authenticity - The bunkers and greens are designed in an austere fashion, with uncomplicated (often geometric) shapes. The remodeled 10th and 14th greens have unusually (prehistoric looking) sharp ridges bisecting the surface. The bunkers tend to have flat sand surfaces with prominent grass faces. Mr. Hanse used approximately the same bunkering style at Waverley here in Portland, a renovation which transformed and improved the course dramatically. Despite the bold nature of the hazards and greens, everything about the design is understated. Further augmentation and shaping of the features was unnecessary.
3. Predictable - After struggling all week in NY/NJ, I had a nice round at Sleepy Hollow. After making a big fuss over a 10 foot birdie putt on the short par-5 6th hole, where I asked everybody how the putt broke, and then pushed the putt way off line, I got very energized and engaged, and played well the rest of the day. Everybody sort of let me be for the rest of the round. The caddies and my host didn't offer too many suggestions. The senior caddie stepped in and changed my club selection on the par-4 15th "Punchbowl" hole. Thoughtful advice was also given on the tee shots at #14 and #17. For the experienced golfer, a course like Sleepy Hollow is logical and predictable. Even on the first try, I needed limited input, as the course provides good visual cues where to play. In general, you could tell what needed to be done, and in my opinion that is an admirable trait. Sleepy Hollow offered an excellent balance of challenge, predictability and forgiveness for missed shots. Not too easy, and not too hard.
My day at Sleepy Hollow was the rare occasion that a course excited my senses, and inspired me to play better golf.