I ride a 75cm in all conditions. I played with trying to stay high on the mast but with the way I ride, I prefer a shorter mast that allows a dynamic riding experience that contours the water. I've found that to be a far more natural way for me to ride swell. All the new foils breach great and super stiff masts handle these breaches great as well. Most would argue 75cm is pretty short and I'd agree that 80cm is sufficient for most, but when I ride an 85cm, I'm a full on kook again.
Nothing but advantages to shorter masts in my mind as well. Especially the heavier you are. You will always have less mast underwater, it will be stiffer and it will be a tiny bit lighter (also cheaper). It takes some practice as mentioned but these days the 78cm One mast is the longest I use, even going upwind in junky 4 meter swell. Unless you're racing, don't see the need.