Just to say, though - maybe I've been duped and/or conditioned, but two par 5s and two par 3s a side "feels" right to me. I can play three or four Par 4s in a row and enjoy them and not give it a second thought; string together three Par 5s, on the other hand, and I don't think I'd have much fun (maybe because I'm an average golfer at best; maybe because I think a really good Par 5, let alone a great one, is rare); same goes for Par 3s -- in most case, they simply aren't all that interesting to me except in relationship to what's come before. Not a rule that's set in stone, obviously, or even a demand or expectation on my part -- I just think that, however it developed, the 4-10-4 approach can not only be reasonably defended, but has some real positives on its side.
Peter