To be honest, during the Philly Open this year, I found the gnarly grassed faces around some of the bunkers to be overly penal. Despite my poor play, I only had one odd situation with a bunker face on #18, but my playing partners had a few more. One nearly lost a ball about 2-3 steps from the right edge of the 3rd green. We ended up finding it, but he had to take an unplayable lie. Meanwhile, my awful skanked long iron that missed right of the right bunker by 10 yards was in much better shape.
The severity of the penalty when missing a green by a couple steps compared to the severity of missing a green by 10-20 yards doesn't add up.
I absolutely love Merion, it's difficult to find anything to complain about, but these bunker surrounds are the only thing on the entire course that I don't understand. I'd be surprised if the current conditions of the bunker surrounds were the same come US Open time...Unless, perhaps given the shortish nature of the course, the severity of these surrounds will be thought of as an added defense. Personally, I think the course can hold it's own without this feature.