Same here. I am 100kg, and although I like most a 7'3" 29"3/4 105 liters, I tend to use a 7'11" 29"1/2 115 liters when I need more paddling speed (shifting peaks). And although the 105 liters board is actually stabler in chop, it is definitively more tiring: its movements are more predictable, but you must be reactive in all direction, whereas with 10 liters more, you have more lengthwise stability and can relax a bit more.
Also, low volume is so great in hollow conditions, but in my place, all surfers crave hollow conditions, so peaks that would benefit from a low volume SUP are packed with excellent shortboarders. So a bit more volume allows to flee the crowds and enjoy weaker peaks alone.
I agree.
The lower you go the more you move away from the benefits of SUP ( within reason).
