rpm mode works best for me. Boat is weighed to capacity , then you find your desired speed and wake, then set that rpm and 0 speed fluctuation. Perfect!
No matter how hard the rider pulls out, how sharp you turn the boat, speed is always exact! Wake is always perfect.
It is what I as well as my six other crew members use on their boats(star, BU, sanger, SAN, B52, Enzo) as well. Try it, you wont use wakeboard mode again.
If your wakeboard mode is working for you - then dont switch, but if its not holding true and crisp at all times, then try rpm, it works unbelievably well.