I have just a little to add, since I've played Shinnecock just once and firmly believe that to really *GET* a course, you should see it multiple times over multiple conditions. I had a lot of preconceived notions going into the round, some held up, others didn't.
Conditions of my round were fog on the front nine w/ a brisk wind picking up on the back.
Fescue: I didn't think the fescue was terribly penal. By that, it was further away from lines of play than I would have expected. It was thicker than I had thought too, which made it probably a half shot penalty if/when you got into it. I didn't drive the ball great and the only time I was in it was on #2. In contrast, Chicago GC's fescue is much closer to play, but is a lot thinner and much easier to play from. I think both styles can be ideal, but a course w/ heavy and close OR light and far away is either too penal or a waste of time.
Fairways: Our host pointed out how narrow the fairways were cut for the '04 Open. Holy narrow, Batman....I felt guilty for missing one after that. I think that makes it wholy unfair to compare daily play to Open play for this thread. They were also firm, but not overly. 36 holes on Winged Foot W/E gave me shin splints in comparison.
Greens: They were just aerified, so they weren't up to normal speeds, but I could see how short siding yourself would be a bad deal. Subtle breaks, I can see a golfer missing a LOT of 10 footers that they would expect to make.
Recovery shots: I never felt like there wasn't a spot to miss it. Again, short siding was a losing proposition, but if you long sided you had a chance to get up and down. No huge rollercoaster pitches that had to be thrown up way high. The ground game was in play around the greens, which made it a lot of fun. I even made an up and down from the front bunker on #7, which made my day.
Routing: This is what makes SH what it is. No holes are completely over the top difficult, but there are no breaks during the round. Each hole stands by itself and the sum of the components make it epic. You're allowed to have FUN on every single hole, all the while having a larger goal of putting 18 holes together and circle a number at the end of the day. Do other courses have better holes than found at SH? Yes. But I've never played another where they all had the feeling of beginning something completely new and fun the moment you stepped on the next tee box. If you allow yourself to get down and beat yourself up after a bad hole, I can see the problems compounding. If you're good at getting over a bad shot or hole, you can move on with great success at Shinnecock. Moreso than any other course I've played.
I shot 79 after hitting the purest 4 iron of my life on #18 from the back tees. I didn't hit the ball great, but was proud of how I played each individual shot. I don't think even it I had played it 50 times I'd ever be close to shooting even par, but it didn't strike me as something that would ever torture me over 18 holes. Although I could see #11 putting even the most level headed golfer in the loony bin.
Definitely one of the best experiences of my golfing life and I can only imagine playing it and NGLA on the same day. What an incredible education that would be.