Mark, I agree. But I also disagree-- if this gets too objective, what happens to all those heated arguments comparing course difficulty? And to take that a step further, I recall a long tradition of arguing about the length of various courses. We had one race that we called the "Fort Dupont Mystery Distance Race". I guess someone could have measured it but that would have spoiled the fun.
Actual measurement can also burst many a bubble. I was really proud of my performance at the Springbank 12 Mile Road Race one year. I finished something like 12th place, but I figured out that everyone ahead of me had run at the Olympics so I laid claim to being the first mortal finisher. And I had made a tremendous breakthrough in pace. Until I found out from Bob Baumel that the Springbank 12 Mile was something like 9.8 miles long!
Seriously I have come to be pretty skeptical about "common wisdom" as to course difficulty. I'm inclined to give a little more credence to folks who actually run lots of races. But I'm also curious to see what results we get from course profile analysis.