Before Olympia Fields got the US Open, Mark Mungeam did the work on the North Course with some "suggestions" from the USGA. The work was well received (and well done) but the course was criticized for some early round low scoring due in large measure to a USGA decision to cut the rough anticipating growth that came later than expected. As the tourney went on the North proved to be a fine test. The USGA had a number of logistical problems with Cook County officials, due in part to its insistence on handling the issues on its own without help from those who "understood" the system, which may account for OFCC's failure to obtain a repeat. I note it held a successful US AM and LPGA Championship.
The South work was more recent and done by Steve Smyers. Our own Jeff Goldman was the club chair on the project. I submit that the critique posted is a bit unfair. The course is much improved for the work and has been well received by members. Participants at the recent US Am also responded favorably.
As for OFCC being the sternest test in the area from the back tees (altered or otherwise) I suspect many who have played Butler might disagree. Medinah 3 from the tips is also a candidate and Rich Harvest, if one is considering difficulty alone, is in the team picture. None of these are necessarily better, just harder.