With the great clubs and balls that WGT has given us and the accuracy of them, a par 4 of 500 yards is not what it used to be.
A good drive with neutral wind can get out to 300 to 310 pretty easily. That leaves you 190 to 200 in or a 4 to 5 iron on WGT. Obviously in real golf we aren't as accurate, well I'm not averaging 300 yards per drive and at 90% accuracy. I also rarely fly a 4 iron within 5 feet from 210 yards in real golf either, on WGT it happens fairly often.
I like a course like Pinehurst because in real golf, it gives you a good variety. The Open is a little more severe, they eliminate a couple of par 5's and make them par 4's and lengthen everything they can. However even in real golf, it is a challenge but here are birdie holes out there, I never have played the course and walked away thinking that it was not fair. I can't say that about all the US Open courses that I have played in real golf.