This morning, there was a surprise swell (6ft at the buoy), so I took my powerful wave 6'10"
I had a blast, why? because it is 120l for my 100kg (as you can see it floats me, and at 30" wide this is not a toothpick), and thus the power it gets from the wave has nothing to do with the prone surfboard!
This is the difference: the volume. Prone surfers do not realize how much more power and speed you get from the wave with more board volume. The trick is the paddle allows us to harness this power: the result: insane fun.
I was alone, making sections, carving rollers all other the place... and was joined by a prone surfer. He just get caught in the foam and didnt manage to do more than just struggling to keep with the shoulder, as he was bogged down because of the low volume of his board (although near 7'), on these 7s period waves (and also he was not as well placed as me, as I was able to see the waves coming better). Granted, Kelly Slater I am sure would have outshined me even on a toothstick. But I am not Kelly Slater, and nor nearly all the prone surfers I see at my location.
Later, the waves backed down, I took my 6'8" fish-like SUP. And yesterday I had a blast on my mini-simmons 6'10" SUP.
So, why do you want me to leave 6'10" SUP where I have insane fun exploiting the wave to the max, and take a prone shortboard where I will just grovel in the foam?
PS: Not everybody likes ShortSUP, and it is OK. A lot of people will have much more fun on a 8' or 9' board. But the idea that a ShortSUP is like a prone Shortboard is ridiculous.
PS: on the aesthetics, SUP is not so bad