The transition to Legend tees evened up the courses in my opinion.
Today my average is around 65 and that is about what I score on all four of them. Prior to the legend tees, St Andrews and Kiawah were at least 3 or 4 strokes easier. It is also important to note that BPB and Oakmont are par 70's so 5 under on those give you a 65 while 5 under on the other two give you 67. I think that WGT has done a good job of making the courses more even for the Legends tier.