The setup at Pinehurst #2 in 1999 was, by far, the best I can recall in the past 4 decades. The shorter rough "suckered" players into trying to advance the ball to the greens. The rough at Oakmont suckered many players into thinking they could advance the ball back to the fairway. Payne Stewart won at 1 under. With two holes to play there were four players who had a chance to win. They were Stewart, Mickelson, Woods, and Singh, four of the top players in the world. Great setup, great finish, with 4 great players. Beat that! It seems to me that if the rough at Oakmont (and other Open venues) were a little shorter, we would see more exciting attempts to advance the ball to the greens with very little improvemnt in the scores.
I too like the idea af a few driveable par fours. It seems to me that the risk-reward should be balanced so that many players will be tempted to try, not just the desperate, the stupid, and those out of contention.
Jim