They seemed quite different to me as well, but I noticed that in both Bill Starr and Mark Ripptoe's programs that they recommend either Power Cleans or Barbell Rows (almost as if they're interchangeable). Bill Starr was quoted as saying that if you could only do one exercise, the clean is the one to do (although I think he was referring more to a squat clean), and Ripptoe lists the Power Clean in his big 5 along with the squat, deadlift, bench press, and shoulder press.
I think an area where I could improve is the upper part of my deadlift. Once I hit 405 I started to struggle a bit while trying to get upright.