My home course, Pumpkin Ridge (Witch Hollow), has suffered somewhat because of the longer ball. An unusual aspect of Witch Hollow is that the par 4s are virtually all medium length, and from the blue (second, about 6500 yards) tees, I rarely have a mid iron approach, when I could expect 3-5 of them per round 10 years ago. The championship tees are about 7,050 yards, so I can move back there in the summertime, where the course plays more interesting for me. 6500 yards is plenty during the wet season in Oregon.
I'd guess the average handicap index of the Pumpkin Ridge membership has dropped by about 2 points in the last 10 years.
Perhaps the great classic courses in the country are not affected as much, because they defend par with sloped greens and severe greenside hazards. Of the courses I play regularly, Pasatiempo plays at about the same difficulty as always, and Stanford seems about one stroke easier. In each case, I still get to play a wide variety of shots.
The courses that lose the most from the longer ball are flat, wide-open, 6500 yard courses, where the primary defense is length. There's a course near Marysville, California named Plumas Lake, which was once listed as a top ten public course by Golf Digest (about 25 years ago). It is a rather flat 6200 yard course, and I imagine it's sort of a pitch and putt now.
I just want to approach greens with a wide variety of clubs.
This thread seems to have been turned into a discussion about Merion.