My personal opinion on the tournament set up for Merion is that there are some significantly unfair (some circles would say illegal) pin locations. You should be able to have a ball come to rest and then stop within 18 to 24 inches of the cup. There are at least 3 pin placements where you can have an uphill putt, putt the ball the needed distance, but if you miss the target the ball will stop and then begin rolling backward (sometimes all the way off the green).
Again, I think it is totally unfair.