There's a difference in spec between the new and old rapture irons if you look closely, the new rapture have an extra 0.5 point for precision. This might not sound much but i've used the old rapture irons since released and since switching to the new set i've noticed that there IS A DIFFERENCE ! The good thing is it's definite a lot more precise in terms of direction and yardage, but ONLY if you ding the shot (hit perfect). It's given me a lot more confidence in my game knowing that you will get the result you want almost every time (allowing for "the beast" factor !).
With the driver and fairway woods you're correct in that there's absolutely no difference. I guess it just a marketing ploy to make it sounds like they've upgraded the product with a NEW model ! lol !