Yes, the switch from PP to zo made changes. With PP , you could slow the boat quite a bit and get the rebound off the 2nd wake to shoot you up on the boat easier. That's the thought behind the stretchy ropes, but they don't quite work the same way.
ZO is so quick to react, and new motors are more powerful. So, the speed swing is much less. The stretchiness can help some skiers, BUT I think the main thing is trying to ski with the same % of stretchiness that you can.
I know I've skied with certain ropes too long...they go from a certain amount of stretchy to nothing at all...steel cables. It's added another variable.
I ski with a guy that came to ski with a new rope. He went from running deep 39 to missing 38 after 38. He got super frustrated, and about 5 days later, he mentioned his rope was new. We put my old rope back on, and he went right back to mid/deep 39. Pay attention to all your changes.