That is a tough hole, although I was able to birdie it two out of the four times I have played it. Besides the length which leaves you with about 180 or so for a second shot, the landing area to get the ball to stop is very small. I hit one shot about 10 feet long that rolled to the back edge, another 5 feet short came back off the front of the green.
There is a false front that you have to carry to get close and if you go back the pin 10 feet it won't shot. I think that as we play Merion more it becomes important to take more notes than usual. There are a couple of holes that if you miss you end up 30 feet away instead of the 10 feet that you expected. Next year Pinehurst will be similar, you miss 10 feet left and the ball rolls off the green.
I'm not a huge note taker for WGT courses but I think this year it will be needed if you plan on going low or in my case making the cut.